Questions on the Posterior Analytics: First Set

By Simon of Faversham.

Translated by John Longeway

Question 51

            We inquire concerning the part, “nor does a geometer suppose anything falsely,” where the Philosopher says that although the geometer, wishing to demonstrate, supposes a line that is not straight to be straight, and what is not bipedal to be bipedal, he does not suppose it in his demonstrations. Therefore it is asked whether geometry in its suppositions accepts something false.

            And it is argued that it does since everyone who supposes that something is of a sort that it does not supposes falsely, but geometry supposes something to be of a sort that it is not, for it supposes a line to be straight which is not straight, and something to be bipedal which is not bipedal; therefore etc.

            Again, everyone who understands anything otherwise than it is understands falsely, but geometry understands a reality otherwise than it is, for it understands a magnitude to be abstracted from sensible quality, and yet in truth no magnitude is abstracted in being; therefore etc.

            The opposed view is apparent from the Philosopher, for he says that although geometry supposes a line extended in a plane to be bipedal even though it is not, it does not accept anything false in its demonstration.

            It must be held that geometry in its suppositions does not accept anything false, and to make this clear it must be considered that whenever some two things are related so that one is prior and the other posterior, it is possible to understand the prior while not understanding the posterior. For it is always possible to understand all those separately of which one is outside the formula of the other. But the posterior is outside the formula of the prior, and therefore it is possible to understand the prior while not understanding the posterior, for instance, to understand animal while not understanding human being.

            Again, even though some two might be conjoined in being, if they are diverse in their formulae it is possible to understand one separately while not understanding the other. And this is apparent since the intellect is a more immaterial power than are the senses, but the senses can sense one of two things conjoined in being while not sensing the other, as is apparent with whiteness and sweetness in milk.

            But now, it is the case that quantity precedes every sensible quality in matter, for according to Boethius, of all its accidents quantity comes to matter first. Again, sensible quantity and quality are distinct in formula, and therefore the intellect can understand quantity while not understanding sensible quality, and since understanding this without that does not occur except in abstracting this from that, therefore the intellect can abstract quantity from sensible quality. But then geometry can abstract quantity from sensible quality and abstracting in this way is not a falsehood, but on the contrary, as the Philosopher says in Metaphysics XII, each is best considered when it is considered as separated from that to which it is conjoined in being accidentally. Since, then, quantity is only accidentally conjoined to sensible quality in being, quantity is best considered when it is considered as abstracted from sensible quality. Therefore geometry, thus abstracting in its demonstrations and suppositions, does not accept anything false.

            Again, geometry does not accept anything false in the sensible extensions it makes, and to make this clear it must be considered that, as the Philosopher says in On the Soul III, whatever our intellect understands it understands in sensible images. For it is necessary for the intellect in understanding anything to view images. Now the way in which the intellect views images in understanding something is taught by the Philosopher in Of Memory and Reminiscence, for he says when we wish to understand human being we first form in our imagination a human being of determinate quantity and determinate figure and so on for the other determinate accidents. Nevertheless, that which we understand per se is not human being as imaged or imagined in this way, but human being without qualification, so that in abstracting from these images afterwards we understand human being without qualification. It is the same in the matter at hand, geometry, wishing to demonstrate something about a bipedal line, extends a sensible line which is in truth not bipedal, but from that sensible extension it forms for itself an image of a bipedal line. And so, forming an image of a bipedal line, it then comes to understand a bipedal line without qualification, so that it does not understand that line which is extended thus, nor does it demonstrate anything of it, but with the presence of an extended sensible line it understands a bipedal line without qualification and demonstrates something concerning it, and therefore, although it supposes a line to be bipedal that is not bipedal, it does not accept anything false, since it demonstrates nothing concerning it.

            In response to the arguments, as for the first, when it is argued “everyone who supposes that something is of a sort of which it is not” etc., I grant it. And in response to the minor premise, I hold that geometry does not directly suppose a line that is not straight to be straight, but we say that it supposes a line that is not straight to be straight because upon presentation of a line that is not straight it immediately forms an image for itself of a straight line, and so it supposes a straight line. But supposing it in this way it does not suppose something false, but it has an image of straight line upon the presentation of a line that is not straight, as we said.

            In response to the other argument, when it is argued “every intellect that understands a reality otherwise” etc., I hold that every intellect that understands a reality to be otherwise than it is is false. And you say, “but geometry understands a reality otherwise than as it is” etc. I reply that it understands quantity to be abstracted sensible quality, and this according to its formula, and this is true since it does not include sensible matter in its formula, but if it includes any matter at all this will be intelligible matter. Therefore it supposes it as it is. Now it is true that if a mathematician were to suppose quantity to be abstracted from sensible matter, and this according to real being, he would suppose something false, but he does not suppose this, and so he does not accept anything false in his suppositions, as has been seen.

Question 52

            “But just as A not being in B individually . . .” —we inquire concerning this part, in which the Philosopher shows that just as there are some immediate propositions among affirmative propositions, so also among negative propositions, and therefore it is asked whether any negative proposition is immediate.

            And it is argued that none is, since no proposition that is true accidentally is immediate, but every negative proposition is true accidentally; therefore etc. The major premise is obvious since an immediate proposition must be true per se. The minor premise is also obvious, for the Philosopher in De Interpretatione 2 says that this proposition, “the good is not bad,” is not true unless it is because this proposition is true, “the good is good.” Therefore every negative proposition is true through another, since it is true through an affirmative proposition, and therefore every negative proposition is true accidentally; therefore etc.

            Again, an immediate proposition is one to which no other is prior; but another is prior to every negative proposition, for an affirmative proposition is prior to every negative proposition; therefore etc.

            On the other hand, it is argued that every demonstration without qualification is from immediate premises, but some negative demonstration is a demonstration without qualification; therefore etc. But every negative demonstration is from some negative proposition, therefore some negative proposition is immediate.

            It must be understood here that there is some immediate negative proposition to be found, and the reason for this is that if some negative proposition is mediated it is obvious that it is demonstrable; if, then, it is to be demonstrated, it must be demonstrated through some prior negative proposition. And a negative proposition by itself will not suffice, but some affirmative is required with it, for a demonstration cannot be made from negative premises alone. If then some negative premise is mediated it will be demonstrated through a negative proposition, along with which an affirmative proposition is also assumed. Then I ask about the negative proposition which proves it, whether it is mediated or immediate. If immediate, we have what was proposed. If mediated, it will be demonstrated through another, and so it will either proceed to infinity in negative propositions, or else some immediate negative proposition will be found. But proceeding to infinity in negative propositions is absurd, since there is an affirmative proposition accompanying each negative one in the proofs, and if there were a procession to infinity in negative propositions there would also be a procession to infinity in the the affirmative propositions, the opposite of which the Philosopher shows below. For he shows that neither upwards nor downwards nor in the middle, nor to one side can there be a procession to infinity in affirmative propositions.

            Again, this can be explained in a second way since every proposition that is per se in the first way is immediate. Now some negative proposition is per se in the first way, therefore etc. The major premise is obvious since in a proposition per se in the first way the predicate is related to the subject as the formal to the material. So as form is immediately in that to which it belongs, so in a proposition per se in the first way the predicate is in the subject immediately. Therefore a proposition that is per se in the first way is immediate, and I speak of such a per se proposition in which the genus is predicated of the species, since at least this sort is purely per se in the first way, and also, according to one opinion, when a species is predicated of the individual. Therefore every proposition per se in the first way, at least every one predicating a genus of its species, is immediate. The minor premise is obvious since just as this proposition is per se in the first way, “a human being is a human being,” so this is per se in the first way, “a human being is not a non-human being,” since human being has that it is human and that it is not non-human through the same thing. But human being has that it is human being through its substance, therefore it also has that it is not non-human through its substance, and therefore just as this proposition is per se in the first way, “a human being is a human being,” so also is this, “a human being is not a non-human being.” For something is a being and one through the same, and it is a being in a species and distinct from each other in species through the same; therefore human being has that it is human being and that it is distinct from every other, so that it is not non-human being, from the same.

            It must be noted that just as it is possible to find different affirmative propositions per se in different ways of saying per se, so it is possible to find different negative propositions. For just as this is per se in the first way, “a human being is a human being,” so also this is per se in the first way, “a human being is not a non-human-being.” And just as this is per se in the second way, “a human being is capable of laughter,” so this is per se in the second way, “a human being is not incapable of laughter.” And just as this is per se in the fourth way, “what is ensouled is alive,” so also this, “what is ensouled is not non-alive.” The major and minor premises are apparent, then, so there will be some immediate negative proposition to be found.

            And you might say that it does not seem that a proposition per se in the first way is immediate, at least not every one of them. For this does not seem to be per se in the first way, or even immediate, “a human being is a human being,” nor even this, “a human being is an animal,” for the Philosopher says that that proposition is not immediate of which the predicate and subject are in some whole, but these are of this sort, therefore they are not immediate and consequently they are not per se in the first way. To this it must be answered that more is required for a proposition to be said to be mediated than the subject and predicate being in the same whole, for it is required that the predicate be distinct through its essence from the subject. I can prove this, for only that is demonstrable of which another is a cause. Now another is a cause of no inherence unless in that of which the predicate is distinct through its essence from the subject, for if the predicate is the same essentially, in this way another is not the cause of its inherence, for there is not any cause why a human being is a human being. It is required, then, that the predicate be distinct in its essence from the subject for a proposition to be mediated.

            Therefore, there is an immediate negative proposition. Nevertheless, for each negative proposition there is a prior affirmative one, since just as the first complex in affirmatives is that a being is a being, so the first complex in negatives is that a being is not a non-being. Therefore just as non-being is related to being, so the first complex in affirmatives is related to the first in negatives. But non-being is posterior to being according to the formula under which it is understood, which can be proved since what is first grasped by our intellect is being. But non-being has the formula of a being insofar as it is understood, not because I understand it to be a being when I understood non-being, but because in understanding it is necessary to attribute something of being to it, insofar as the intellect reasons about it. Therefore non-being presupposes being. And therefore the first complex in negative propositions presupposes the first complex in affirmative propositions. And therefore to every negative proposition, insofar as it is immediate, there is a prior affirmative proposition.

            In response to the arguments, as for the first, when it is argued that “no proposition which is true accidentally” etc., “accidentally” can be taken in two ways, either as it is opposed to what is primary or as it is opposed to what is per se. Taking “accidentally” as opposed to what is per se, the major premise is true, for it is necessary for every immediate proposition to be true per se. Speaking of “accidentally” as opposed to what is primary, it is not true in every case, for it is not true that no proposition that is true but not primary is immediate, for this proposition, “Socrates is a human being,” is not true primarily, since this proposition is true prior to it, “a human being is a human being,” but nonetheless it is immediate. And you hold in the minor premise, “every negative proposition” etc. If you understand this about “accidentally” as opposed to what is per se, in this way the minor premise is not true, for as this proposition is true per se, “a human being is a human being,” so also this, “a human being is not a non-human being.” If it is taken as opposed to what is primary, in that case it is true, since no negative proposition is true and primary. And therefore the Philosopher does well to say in On Interpretation that this proposition, “good is not bad,” is not true unless it is because this one is true, that “good is good.” For the first is true prior to some true proposition, but this proposition is an immediate negative.

            In response to the other argument, when it is said, “an immediate proposition is that in which” etc., the text can be exposited in this way: an immediate proposition is one to which another is not prior, that is, an immediate proposition etc. is that in which there is no prior proposition by which the predicate is demonstrated of the subject. And I hold that there is a negative proposition to which there is not prior affirmative proposition that is like the middle term between the subject and predicate for demonstrating the predicate of the subject, for some negative proposition is to be found between the subject and predicate of which there is not any middle term, abut the predicate is immediately removed from the subject, and therefore it is an immediate negative.

Question 53

            We inquire next concerning a certain omission, for the Philosopher, assuming a difference between demonstration that it is so and demonstration why it is so, says that demonstration why it is so is made through the cause, but demonstration that it is so is made through the effect and from what is posterior. Therefore it is asked whether demonstration that it is so is demonstration without qualification.

            And it is argued that it is, since every demonstration that makes one know is a demonstration without qualification, for a demonstration is a syllogism that makes one know, but demonstration that it is makes one know, therefore etc.

            Again, everything that proceeds from what is primary, true, and immediate is a demonstration without qualification, but demonstration that it is is like this; therefore etc. The minor premise is obvious, since just as it is possible to find and immediate cause, so it is possible to find an immediate effect; therefore just as demonstration why it is so proceeds through something immediate, since it proceeds through an immediate cause, so demonstration that it is proceeds through something immediate since it proceeds through an immediate effect; therefore etc.

            On the other hand, it is argued that only demonstration why it is so is demonstration without qualification, as the Philosopher suggests in the text. But demonstration that it is so is not demonstration why it is so, for that it is and why it is differ. Therefore etc.

            It must be understood that, as the Philosopher contends in Metaphysics IV, each natural thing is determined by a certain operation, and it is capable of this operation it is called a singular, and when it is not it is not called a singular, unless equivocally. For instance, there is an operation proper to human beings, namely reasoning, and when something is capable of reasoning it is called a human being, and when it is not capable it is not called a human being except equivocally, as, for instance, in the case of a sculpture of picture. From this it appears that as something is related to the operation following upon the form, so it is related to the form that is the principle and cause of that operation. But the proper operation of demonstration is to make one know, for demonstration makes one know through that nature by which it is demonstration, therefore just as a demonstration is related to what makes one know so it is related what is demonstration, so that what makes one know without qualification is demonstration without qualification, and what makes one know in a certain respect is demonstration in a certain respect. Now demonstration that it is so does not make one know without qualification, for demonstration that it is so is either through the effect or through a remote cause. Now one does not know about a reality without qualification through a remote cause, for knowledge without qualification of a reality is had through a complete and distinct cognition of it, but there is only a confused cognition through a remote cause, therefore demonstration that it is so as it proceeds from a remote cause does not make one know without qualification.

            Again, neither does demonstration that it is so as it makes one know the cause through the effect make one know without qualification, for every cause exceeds its effect in substance and perfection, and therefore no effect can perfectly show the substance and power of its cause, therefore a demonstration that it is so which demonstrates the cause through its effect does not make one know without qualification.

            Therefore demonstration that it is, since it proceeds through a remote cause or through the effect, is not demonstration without qualification, nevertheless demonstration that it is is demonstration in a certain respect, since it makes one know in a certain respect. For as something is related to being so it is related to cognition. Now the effect is in the cause, and conversely, for everything is in everything, causes in effect and effects in causes; and therefore it is necessary that the effect be cognized in the cause and conversely. But the effect is cognized in the cause by a cognition without qualification, while the cause is cognized in the effect by a cognition in a certain respect. Therefore one cognizes the cause through the effect in some way, and this by cognition in a certain respect. It must be held, then, that demonstration that it is so is not demonstration without qualification, but only demonstration in a certain respect.

            And in response to the arguments opposed to this view, the solution is apparent, for when it is said “everything that makes” etc., I reply that everything that makes one know without qualification is demonstration without qualification, for as something participates in an operation, so it also participates in the form. And as for what you say in the minor premise, it is true in a certain respect, and therefore it is a demonstration in a certain respect.

            In response to the other, when it is said, “every demonstration” etc., the Philosopher says that demonstration is from what is primary and true, better known, prior, immediate and the cause of the conclusion. Therefore when it is said in the major premise “every demonstration” etc., and this is true if those primary and true things are the causes of the conclusion, the cause, I mean, in both cognizing and being. Such are the principles of demonstration. And as regards the minor premise, I hold that demonstration that it is is not from such as make one know without qualification nor from such as are causes in being, so the demonstration that it is is not demonstration without qualification, but demonstration in a certain respect.

Question 54

            We inquire about the part, “But since knowing why differs” etc., in which the Philosopher, while settling questions about the subalternation of the sciences, holds that those sciences subalternate of which the subjects subalternate, in which the Philosopher suggests that the unity of a science arises from the unity of its subject, and difference between sciences from the difference between their subjects. Therefore, it is asked whether the unity of a science arises from the unity of its object or subject.

            And it is argued that it does not, since if the unity of a science arises from the unity of its subject, then different sciences cannot consider about one and the same thing; the consequent is false, therefore the antecedent is as well. The falsehood of the consequence is apparent, for different sciences consider the same thing, for instance, logic and metaphysics do, which are different sciences since one concerns realities and the other formulae, but they nevertheless consider the same thing, namely beings. Therefore etc.

            Again, if the unity of a science were from the unity of its subject, then the difference between sciences would arise from the difference between their different subjects. Therefore it cannot be one science. The falsehood of the consequent is apparent, since the same science concerns substance and accidents, as is apparent from metaphysics, but subject and accident are not the same in genus or species or number; therefore etc.

            On the other hand, it is argued that we see in practical sciences that the unity of an operation is measured by the unity of what is operated on. Therefore it is the same in the speculative sciences, and the unity of cognition is measured by the unity of the cognized. But a science is a certain cognition, and its subject is what is cognized by it. Therefore the unity of a science is taken from the unity of its subject.

            It must be said in response to this that the unity of a science arises from the unity of its subject. For a science is related to its subject as a capacity to its object, and the reason for this is that just as the primary object of a capacity is that which is first grasped by that capacity, and under the formula of which others are grasped by it, so the subject in a science is what is cognized primarily in a science, and that under the formula of which every other is cognized. So since the subject is what is cognized primarily, the Philosopher says in the first book of the text that it is necessary to cognize beforehand concerning the subject both what it is and that it is, for if the subject were unknown, every other would be unknown. Therefore as a capacity is related to its object, in the same way a science is related to its subject. But the unity of a capacity is from the unity of its object, and therefore it is necessary to assume that the unity of a science is from the unity of its subject.

            Again, this is explained since the progression of a science is a certain motion of reason, but a motion of reason is like natural motion, and therefore the progression of a science is like a natural motion. But the unity of a natural motion is received from the unity of its end, therefore it will be the case in the progression of a science that the unity of a science is received from the unity of its end. But the end is the subject of the science, therefore the unity of a science is received from the unity of its subject, and this is true in general in both the speculative and the practical sciences. For in the speculative sciences the end is the cognition of the subject, and in the practical sciences the end is the establishment of the subject. So it appears in geometry that its end is the cognition of magnitude, which is the subject of that science, but the end in architecture is the construction or establishment of a house. If, then, the subject of a science is related to it under the formula of end, but the progression of a science to its end is like a certain motion, then the unity of a science is measured by the unity of the subject. Because of this the Philosopher says afterwards in the first book of the text that that science is one which is of one genus as its subject.

            But next it must be observed that the unity and diversity of a capacity do not arise from the unity and diversity of its every object, that is, not from its material object, but from the unity and diversity of its formal object. For insofar as they differ according to material differences objects communicate differently under a single formal formula, and it is obvious that they can fall under a single capacity. For instance, white and black differ by material difference of color, but nevertheless, since they agree under the formula of color expressing what color is, therefore they are one object with respect to the unity of vision. And therefore a material diversity does not diversify the capacity. In the same way, it must be held that unity in a science arises from the formal unity of the subject, so that however different they are according to material or formal differences, as long as they agree in one formula of the subject expressing what the subject is, they may fall under one science. So when questions are settled in metaphysics concerning being as its subject, then man, stone, or whatever other beings, however they may differ formally or materially, fall under the formula of the metaphysician. In the same way, since movable body is the subject of natural science, however different beings are, as long as they agree in the formula of movable body they fall under natural science. And therefore the unity of a science must arise from the unity of its subject considered as its subject, and not from the unity of its subject considered as something belongs to it under the formula by which it is made subject.

            In response to the arguments, as for the first one, I grant that different sciences do not consider one and the same thing in accord with one subject formula, but if they consider one and the same thing this will not be according to one subject formula, and therefore, although metaphysics and logic consider one and the same thing, still, they don’t consider the same thing under one subject formula, since the metaphysician considers being as being, but the logician considers being as formula.

Question 55

            We ask about the part, “but ignorance” etc. The Philosopher, distinguishing between ignorance of negation and ignorance of disposition, holds there that ignorance is a deception produced through syllogism. Therefore it is asked whether ignorance comes to be through syllogism.

            And it is argued that it is not, for that which come to be through syllogism must be a being, since what comes to be through syllogism comes to be from certain definite principles, but ignorance is non-being; therefore etc.

            Again, the Philosopher in Metaphysics II says that there is in this way a middle between being and non-being, but ignorance is not a middle between being and non-being. Therefore ignorance does not come to be through syllogism.

            The opposed view is obvious from the Philosopher, for he says that ignorance is a deception produced through syllogism.

            It must be held that ignorance is of two sorts, namely ignorance of disposition and ignorance of negation. Ignorance of disposition is knowing nothing whatsoever about the thing, and in this way a child who is just born is ignorant of geometry, since he knows nothing about geometry, neither in the universal nor in the particular. For our intellect does not have an intelligible innate in it from the beginning, but it is, as it were, a tablet upon which nothing is written in actuality. For he does not know anything in actuality before learning or discovery, and therefore, since the intellect has no intelligible innate in itself, it has no knowledge, neither in the universal nor in the particular. This ignorance of negation is contrary to knowledge privatively, since privation is a negation of a perfection in a subject naturally suited to it. Now “ignorance of negation” indicates no positive nature, but is a privation of a perfection in a subject naturally suited to it, for it is a privation of knowledge in the intellect. Therefore etc. But the other sort is the ignorance called ignorance of disposition, and it is a deception contrary to truth that someone holds as an opinion contrary to a proposition that is true through a middle term or immediately. So ignorance of disposition can arise both about principles and about conclusions, about principles insofar as one holds an opinion opposed to principles, and about conclusions insofar as one holds an opinion opposed to conclusions. The first ignorance of disposition is contrary to that understanding which is a habitus of principles, but the second is contrary to knowledge, which is a habitus of conclusions. The ignorance of negation of which we have spoken is not a deception through syllogism, but occurs before every syllogism. Now this is innate to our intellect from the beginning, and precedes every cognition that our intellect has of a reality, both universal and particular. But ignorance of disposition of the one sort comes to be through syllogism, and that of the other sort does not. The ignorance of disposition that is contrary to the habitus of first principles does not come to be through syllogism, just as the habitus principles does not come to be through syllogism. But the ignorance which is contrary to the knowledge that is a habitus of conclusions is generated through syllogism. But there is a difference here because the knowledge that is a habitus of conclusions comes to be through demonstrative syllogism, but the ignorance opposed to it occurs through a deceptive syllogism. Therefore it is apparent in this way which ignorance comes to be through syllogism and which does not. But it is true that the ignorance of disposition, which is as much about principles as it is about conclusions, sometimes can be had through syllogism, and sometimes not. Fro one who is not moved by an argument cannot believe the opposite of a conclusion, or of any true principle, but when moved by sophistical argument that he does not know how to resolve he believes the opposite of a true principle. And the Philosopher in Metaphysics IV says that some contradict first principles in this way, persuaded by argument, and some are not persuaded by argument and contradict first principles because due to their lack of erudition or their stubbornness they wish to seek demonstrations in everything.

            In response to the arguments, as for the first, I reply that what comes to be through syllogism is a being, either a being according to formula, or a being according to real, true existence, but it suffices that what comes to be through syllogism should be a being according to formula. And you say, “ignorance” etc., to which I reply that ignorance of disposition is a being according to formula, since as knowledge is a true habitus of conclusions existing in the soul that comes to be in addition to and through primary and immediate truths, thus the ignorance opposed to it is a false habitus that comes to be through a certain false and deceptive syllogism. Now the false, although it is not something which outside the soul, is still a being according to formula, for the good and the bad are among realities, but the true and the false are in the mind, therefore a false habitus is a being according to mind insofar as a mind can believe it through a false habitus, or disbelieve it.

Question 56

            “Questions are equal” etc. In the beginning of the second book of the text the Philosopher accepts that the number of knowables depends on the number of questions, saying “Questions are equal...” But we ask four things, and therefore we ask whether there are four questions.

            And it is argued that there are not four, for a cognition beforehand and a question are not the same, for a question is something doubted, but a cognition beforehand is something known. But if it is and what it is are cognitions beforehand according to the Philosopher in the first book of the text, therefore they are not questions.

            Again, a question which asks by means of “what sort,” or “how much,” is a question. Again, there is a question about the signification of a name, and also a question about the way in which something inheres, and yet these are not comprehended under any of these four; therefore there are more than four questions.

            The Philosopher defends the opposite view, and he says “but we ask four things, if it is, what it is, whether it is, and why it is.”

            It must be said that all questions are reduced in genus to four in number, the reason for which is that every question if it asks concerning the essence of a reality, either asks what it is or if it is, and according to this there are two questions, the question if it is and the question what it is; but if one asks concerning inherence he asks either concerning inherence absolutely considered or asks concerning the cause of inherence, if concerning inherence thus it is the question whether it is, if concerning the cause of inherence, thus it is the question why. Therefore all questions come to four in number. That is, they reduce to if it is, what it is, whether it is, and why it is.

            And the explanation of this is that every questioner seeks a middle term. And an argument for this can be that every questioner takes something as an end, and when he has that he ceases from questioning. Now everyone directed to something as an end seeks a means by which he can arrive at that end, so that everyone who questions seeks a middle term if he questions rightly. This argument seems to be given by Grosseteste, though he doesn’t spend a great deal of time on it. Reason, then, when it is directed to something, seeks a means (medium) through which it can arrive at it, therefore every question is a question of the middle term (medium). But every question of the middle term seeks the middle term, either under the form of middle term or not under that form. If it seeks the middle term under the form of middle term, in this way it is the question why, since the middle term is the same as the cause. Whoever, then, seeks the middle term under the form of middle term seeks the cause, but in this way he asks by means of “why.” But if a question seeks the middle term not under the form of middle term, then either one asks about the middle term with regard to the simple essence or with regard to inherence—if in the first way, there are two questions, namely if it is and what it is, if in the second way, it is the question whether it is. So in this way there are four questions.

            Again, this can be explained in a third way. Questions are equal in number to those things we know, so there are as many questions as knowables. There are four genera of knowables, therefore there are four genera of questions. It is clear that there are four genera of knowables, for everything that is known in the strict sense is either known through the whole demonstration, or through the middle term of the demonstration—if in the first way, in this way whether it is is known, for it is known through demonstration whether the passion is in the subject, for this is the conclusion of a demonstration. But if it is known through the middle term if of a demonstration, either it is known through the middle term under the form of middle term or it is known through that which, as it happens, is the middle term—if in the first way, in this way it is known why, since the middle term under the form of middle term is the cause and why. But if it is not known through the middle term under the form of middle term, but is known through that which, as it happens, is the middle term, since that which the middle term is is the definition, in this way it is known what it is, since definition indicates what, which is known through that which the middle term is, since the middle term is the definition telling what it is that is known. Before what it is we know if it is, so that al-Farabi contends, as Albert reports here, that if it is is not cognized through a categorical proposition, but through a conditional proposition. In this way if we cognize what it is we cognize if it is. Therefore everything that is known is either known through the whole demonstration, and in this way it is the question whether it is, or through the middle term under the form of middle term, and in this way it is why, or through that which the middle term, as it happens, is, and in this way it is known what it is, and when we know what it is we know if it is. Therefore we know four things, so that we also ask four things.

            But perhaps someone will raise a doubt. It seems to be about the question whether it is and the question if it is. And it seems first that whether it is is not a question, for through that which is more a mark of an assertion than of a question a question seems not to be put, but “whether” is more a mark of an assertion than of a question; therefore etc.

            Again, neither does if it is seem to be a question, for something is supposed and something is unknown in a question, for everyone who seeks the middle term is between a pure knower and the pure ignorant, and therefore in every question something is known and something is unknown. But in the question if it is nothing is unknown. For if something were unknown this would be being, but this is not unknown since being is that which first occurs to our intellect. Therefore etc.

            Grosseteste seems to respond to the first, for he says that sometimes there arises a question about something that can be doubted through the mode of the dubitable, and sometimes there arises a question about what can be doubted not through the mode of the dubitable, but the mode of the known. For example, if I say, “I ask whether (an) thunder is,” this is a question about what can be doubted through the mode of the dubitable. If I say, “I ask whether (quia) thunder is,” it is asked about what can be doubted, but not through the mode of the dubitable, for it is asked here through that which is more a mark of an assertion than of a doubt. When, therefore, you say, “through that which is more a mark of an assertion” etc., it is true that a question cannot be put through such about what can be doubted through the mode of the dubitable, but a question can arise in this way about what can be doubted not through that mode. And it is that way here, “I ask whether thunder is.” Therefore a question whether it is is a question which asks about what can be doubted through the mode of the known, as he says. So it is not asked “whether” (quia) so that the word “whether” is properly a mark of interrogation, for then we say “quare,” because when we ask that we might know that it is so, for instance, when I ask, “is man able to laugh,” I ask using “quia,” because I ask that it might be known that it is so.

            In response to the other, when it is said, “in every question” etc., this is true. And you way, “but in the question if it is” etc. I deny it. For something is unknown here, for when you ask if (an) something is, you suppose that that about which it is asked has being, but it asks if it is an essence and a nature, something, therefore, is known there and something is unknown. So then, the question if it is is a question. So there are four questions.

            In response to the arguments, as for the first, when it is said, “the same thing is not both a precognition and a question,” I reply that the same thing is not both a precognition and a question according to the same form, but according to different forms this can easily be, for that which is first a question can afterwards be a precognition with respect to another. For example, we can ask about the subject of a science first if it is and what it is, for we can be ignorant of both, but afterwards, when we know these things, they can be precognitions with respect to those things determined in the science. The same according to substance, then, can in this way be a question and a precognition.

            In response to the other argument, when it is said, “a question through ‘how much’ and ‘of what sort’” etc., I reply that they all reduce to the question whether it is, since every question which asks about inherence is a question whether it is, and in every question that which is asked and that about which it is asked differ in essence, and therefore every such question is called a question “putting it into a number,” but in every such question in which it is asked through “of what sort” and “how much” and such, that which is asked that about which it is asked are diverse in essence, as when it is asked “how large is a man,” “of what sort is a man?” So every question is also a question whether.

Question 57

            It is asked whether the questions are reducible to one another.

            And it is argued that they are not, for opposites don’t reduce to one another, but the questions are opposites; therefore etc. The major premise is obvious, for coldness does not reduce to heat, or conversely. The minor premise is also obvious, for a division is made through opposites, and a division is made between questions; therefore the questions are opposites.

            Again, if the questions were reducible to one another they would be reducible in the end to the question what it is, as well appear below. But the questions why it is and if it is and whether it is cannot be reduced to the question what it is, since then when one cognizes what it is it would be necessary to cognize beforehand if it is and whether it is, which, however, is not true. For I can cognize what a man is and still be ignorant if he is.

            On the other hand, it is argued that all the questions are reducible to a question of the middle term, since every question is a question of the middle term. But the question what is is the question of the middle term, for what it is strictly speaking has the form of middle term; therefore etc.

            It must be understood that, as appears from the Philosopher in Metaphysics X, in each genus it is necessary to arrive at some first and least which is the principle and measure of all those in that genus, and therefore in the genus of questions it is necessary to arrive at some first question which is the principle and measure of all the others. I say ‘measure’ not in accord with quantity, but cognition, for the cognition of this is the measure of all the others. But the question the cognition of which is the principle and measure of all the others, and to which all the others are reducible, is the question what it is. This is apparent since every question has as its end that that which is asked should be known, and therefore it has as its end that by the cognition of which every question is resolved.

            Now every question is resolved by the cognition what it is, for if it is something is cognized when it is cognized what it is, for whoever cognizes what a reality is has a cognition of the reality in the particular and in its own form. But whoever cognizes if it is a reality cognizes the reality in the universal, and in a confused manner. So as cognition of a reality in the particular and in its own form presupposes cognition in the universal, so cognition what it is presupposes cognition if it is, and also, when it is cognized what it is it is cognized whether it is. For cognizing whether it is is cognizing something being in a reality, since whether it is asks about inherence. But whoever cognizes what a reality is cognizes that which is in a reality through that-which-it-is, and therefore whoever cognizes what it is cognizes whether it is. And again, whoever cognizes what it is cognizes why it is, for whoever cognizes what it is cognizes the cause of all accidents existing in the reality, since that-which-it-is is their cause, but ‘why’ indicates cause; therefore whoever cognizes what it is cognizes why it is. In this way, then, when it is cognized what it is every question is cognized, and therefore every question reduces to the question what it is. And the Philosopher suggests this in the text, for when in the beginning of the second book he posits four questions he reduces these to two. For every question asks what the middle term is or whether there is a middle term, for the questions if it is and whether it is ask whether there is a middle term, and what it is and why it is ask what the middle term is. And then he concludes, if every question asks what the middle term is or whether there is a middle term, every question is a question of the middle term. Now what a reality is strictly speaking has the form of a middle term, and therefore according to the Philosopher every question reduces to the question what it is.

            As for the arguments, in response to the first I reply that opposites considered according to their distinct natures are not reducible to one another. Nevertheless, considering one contrary insofar as it has the form of possession and the other of privation, and insofar as one is more prefect and the other less perfect, one reduces to the other, for in every genus the imperfect reduces to the perfect. And when it is said in the minor premise “that” etc., I reply that this is not the case. Although they are different, still not every difference causes opposition and especially not the difference between those of which the cognition of one depends on the cognition of the other, and which are founded on the same thing. But questions are of this sort. Questions are like this because they are founded at the same time on one and the same thing, and the cognition of one depends on the cognition of the other, for even if one opposite is the principle of cognizing the other, still they are not founded at the same time on the same reality. The questions, however, are founded on the same reality, and the cognition of one depends on the cognition of the other.

            In response to the other argument, when it is argued, “if the questions were reducible” etc., this is true. And you prove that it is not, and in response to the proof I reply that a cognition what it is necessarily is a cognition if it is; and you prove that it is not, and in response to this proof I hold that if it is can be said in two ways: either if it is some reality and nature or if it is in actuality. So if it is cognized what it is it is not necessary to cognize is it is in actuality, since being and non-being in actuality are accidents of the nature of the reality, but one who cognizes what it is necessarily cognizes if it is some essence and nature.

Question 58

            We inquire next about the question if it is, and let it be asked whether the question if it is is a question of the middle term.

            And it is argued that it is not, for every question of the middle term seems to be about something mediated, and consequently something having another as a cause, but the question if it is can be about something immediate without another as a cause, for the question if it is can be formed about immediate principles, and even about the first being, which in itself has no cause—for some have doubted that there is a first principle to be posited among beings; therefore etc.

            Again, the middle term strictly speaking is of those two which ‘put it into a number,’ for the middle term seems to presuppose a duality. Therefore every question of the middle term seems to be a question that ‘puts it into a number,’ but the question if it is does not ‘put it into a number,’ but is a simple question, according the Philosopher; therefore etc.

            On the other hand, it is argued that every question that seeks out something concerning the middle term is a question of the middle term, but the question if it is seeks out something concerning the middle term, for it asks whether the middle term is; therefore etc.

            With regard to this, it must be understood that every question seek the middle term. For the reason or intellect, when it seeks something, is directed to the cognition of that which it seeks as its end, and everything directed to something as to an end seeks a middle term through which it can arrive at that end. And therefore reason, when it seeks something, seeks a middle term through which it can arrive at that which it seeks. If, therefore, every question seeks a middle term, every question is a question of the middle term.

            Again, what can be asked and what can be known is the same, so the Philosopher says that those things we ask are equal in number to those we can know. Now every knowable has a middle term, since every knowable is demonstrable, and every demonstrable has a middle term, and therefore everything which can be asked has a middle term. Since, then, everything which can be asked has a middle term, but there is no question except about what can be asked, therefore every question is a question about the middle term or about something under the form by which it has a middle term; therefore the question if it is is a question about the middle term.

            But that some question is a question about the middle term can be understood in two ways: either so that it asks about the being of the middle term or about the essence of the middle term. The question if it is is a question about the middle term since it asks about the essence of the middle term, for it asks whether the middle term has such being that it is some essence and nature, and therefore it asks whether there is a middle term.

            But you will say, “if the question if it is asks whether there is a middle term, and whether it is [quia est] asks whether [an] there is a middle term, then if it is and whether it is do not differ.” With regard to this it can be said that the question if it is asks about the being of the middle term absolutely, but the question whether it is asks about the being of the middle term not absolutely considered, but with respect to the extreme. For it asks about the being of the middle term as it is received as a middle term for demonstrating one extreme term of another.

            But you will say next, “it does not seem, according to what has been said, that whether it is differs from why it is, for it is the question why which seeks the middle term under the form of middle term because of which the predicate is demonstrated of the subject. If, then, the question whether it is seeks the middle term under the form of the middle term because of which the predicate is demonstrated of the subject, therefore etc” I reply that the question whether it is still differs from the question why it is since the question whether it is asks whether there is such a middle term because of which a passion is demonstrated of the subject, but the question why asks what that middle term is. And therefore as what it is and if it is differ, so whether it is and why it is differ.

            But you will say, “through what has been said it seems that the question what it is and why it is do not differ, since the question which asks what the middle term is is the question what it is. If, then, you say that the question why it is asks what the middle term is through which a passion is demonstrated of the subject, what and why do not differ.” It must be replied that the questions what it is and why it is do differ, even though both ask what the middle term is, since the question why it is asks what the middle term is taken as a middle term for demonstrating a predicate of a subject, but the question what it is asks what the middle term is absolutely considered, or that which the middle term is.

            From this a brief division is taken. Now every question asks about the being of the middle term or about its essence. If it asks about the being of the middle term it either asks about the being of the middle term absolutely considered or about the being of the middle term considered as a middle term. If in the first way, in this way it is the question if it is, if in the second way, it is the question whether it is. If it asks about the essence of the middle term it either asks about its essence absolutely considered, and in this way it is the question what it is, or it asks what the middle term is under the form of middle term, and in this way it is the question why it is. For the middle term considered under the form of middle term indicates the cause, but the cause and why it is are the same; therefore etc.

            As to the arguments, in response to the first, when it is argued “every question” etc., I reply that every question about the middle term under the form by which the middle term is of something mediated also has another as a cause; but a question about that which is a middle term as it happen, not considered under that form by which it is a middle term, is surely of something immediate. Since the question if it is is a question about that which is the middle term absolutely considered, and a middle term is not a complex taken in this way, so neither is it mediated, for everything mediated in a demonstration is complex. And you reply, “but the question if it is can be immediate” etc. This is true, and therefore I grant that it is not a question of the middle term under the form of middle term, but a question about that which, as it happens, is the middle term.

            As to the other, I reply that the middle term as a middle term presupposes duality. And you say, “therefore every question seems to be a question putting it into a number.” I reply that this does not folow. For Albert on this part says that that question is a simple question of which the ultimate intention is to know something simple. But a question putting it into a number, or composite question, is one the ultimate intention of which is to know something complex. Now the ultimate intention of the question if it is is to know something incomplex, namely whether that which, as it happens, is the middle term has such being that it is some essence or nature; and therefore the question if it is is a simple question.

Question 59

            We inquire concerning the part in which Philosopher compares definition to demonstration, and since the philosopher proves there that there cannot be definition and demonstration of the same thing, it is asked whether there can be definition and demonstration of the same thing.

            And it is argued that there can be, for there is definition of accidents and demonstration of accidents, therefore there is definition and demonstration of the same things. The major premise is obvious from the intention of the Philosopher in Metaphysics VII and from common usage. The minor premise is obvious from the Philosopher in the text.

            Again, of that of which there is demonstration there is a principle of demonstration. Now there is demonstration of a passion, therefore there is a principle of demonstration of a passion. But the principle of demonstration is definition. Therefore there is definition and demonstration of the same thing.

            On the other hand, definition is of something incomplex and of a per se being, but demonstration is of something complex. Therefore these are not the same, therefore there is not definition and demonstration of the same thing.

            It must be understood here that there cannot be, per se and primarily, a definition and demonstration of the same thing, for demonstration is of what has a middle term, so that every demonstration proceeds through a middle term. But the middle term and the cause are the same, and therefore demonstration is of those which have a mediating cause—I call that a mediating cause through which one is demonstrated of the other. Now there is no definition of things having a mediating cause, for definition is of that thing with respect to that-which-it-is which is in it. Now there is no middle cause between a reality and its definition, for nothing is more immediate in a reality that that-which-it-is. Therefore definition is not strictly speaking of those which have another as a cause, but demonstration is of those which have another as a cause; therefore etc.

            Again, this is obvious from a certain argument which the Philosopher provides in the text, although he does not devote a great deal of time to it. For he says that definition shows what-which-it-is, but demonstration shows that it is. Now to show that it is is to show that this is in that, and therefore demonstration shows this to be in that; if, then, demonstration principally shows this to be in that demonstration is primarily of those the being of which is being in; but those of which being is being in have being with reference to something, not absolutely, and therefore demonstration is of those which have being with reference to something, so that every demonstration is of accidents. But a definition is of those which per se and primarily have a that-which-it-is and an essence, but through essence something is primarily, and therefore definition is of those that have being primarily. But those which have being primarily are substances, therefore definition is of substances. So we have established that demonstration is per se and primarily of accidents, and definition is per se and primarily of substances, but accidents and substances are not the same; therefore, etc.

            So there is not a definition and demonstration of the same thing primarily, nevertheless there can be a definition and demonstration of the same thing, but not primarily, for definition is of those which have essence, and that-which-it-is, primarily, and there is not a that-which-it-is of accidents primarily, but the that-which-it-is of these is caused from the that-which-it-is of substances, and they do not have a that-which-it-is primarily and so neither is there definition of these primarily, but only as a consequence. And this seems to be the solution of the Philosopher in Metaphysics VII, where he says that definition is of primary beings primarily and per se.

            In response to the arguments, as to the first, when it is said, “there is a definition of accidents” etc., I reply that ther eis a demonstration of accidents primarily and definition of accidents, but no primarily, and therefore I grant that there is demonstration primarily and definition, but not primarily, of the same thing.

            In response to the other, when it is said, “of that of which there is demonstration” etc., it is true—of that of which there is demonstration there is a principle of demonstration that it is. But having a principle of demonstration that it is is having a definition that shows this to be in that; and therefore I hold that of that of which there is demonstration there is a principle of demonstration showing it to be in the subject. And as for the minor premise, I grant it, and so I grant that there is a principle of demonstration showing it to be in the subject; but it is by no means necessary that there be a principle of demonstration concerning it that indicates that-which-it-is, at least not per se and primarily.

Question 60

            We ask about the part, “but first that-which-is.” In that part the Philosopher shows which is the way to arrive at that-which-it-is, and he investigates whether the way is through demonstration, division, or syllogism. Therefore it is asked whether that-which-it-is can be arrived at through demonstration.

            And it is argued that it is, since everything that has another as a cause can be demonstrated through that cause, but that-which-it-is has another as a cause. For everything that is other than the first cause has another as a cause, for nothing other than the first cause is a cause sufficient for its own existence. Therefore etc.

            Again, the conclusion of a demonstration can be demonstrated, but some definition is a conclusion of a demonstration, therefore some definition is demonstrated. But that-which-it-is is signified through ostension, therefore that-which-it-is can be demonstrated.

            On the other hand, it is argued that there are different ways of cognizing different cognizables, but what-it-is and that-it-is are different cognizables; therefore etc. But demonstration makes one cognize that-it-is, so definition makes one know what-it-is and consequently demonstration does not. He gives this argument in the text.

            Again, this can be argued: everything that is demonstrated is something complex, but that-which-it-is of a thing is not complex; therefore that-which-it-is of a thing cannot be demonstrated.

            There are three things to be understood here. The first is that that-which-it-is of a passion can be demonstrated by a demonstration without qualification providing the reason why. The second is that that-which-it-is of a subject cannot be demonstrated by a demonstration without qualification, neither a demonstration of that to which it belongs nor of any other. The third is that although the that which it is of a subject cannot be demonstrated without qualification, it can still be demonstrated in a certain respect.

            The first point is apparent in the highest sort of demonstration. A passion is demonstrated of its subject per se and strictly speaking, and from this it is argued that of whatever one of a number of convertible things is demonstrated the rest are also, especially if they are convertible as far as their nature and that-which-it-is are concerned, and that-which-it-is of the passion and the passion itself are convertible in essence and nature. If, then, a passion can be demonstrated of its subject by a demonstration without qualification, similarly its that-which-it-is will be demonstrated of its subject. Nevertheless, that-which-it-is of a passion cannot be demonstrated of the passion, for demonstration is of those for which there is a mediating cause through which it is possible to demonstrate one of the other. But between that-which-it-is of a passion and the passion there not mediating cause, since that-which-it-is of a thing is immediately in what it is in. Therefore etc. In this way the first point is apparent.

            In the second place, it must be understood that the that-which-it-is of the subject cannot be demonstrated either of that to which it belongs or of any other, for the first principle of a demonstration cannot be demonstrated, since then there would be an infinite regress; but that-which-it-is of the subject is the first principle of every demonstration, as is apparent from the Philosopher in De Anima II. And this is also obvious through reason, since the first principle of demonstration is either complex or incomplex. It cannot be said to be complex since there is nothing prior to a principle of demonstration which is first without qualification, and to everything complex there is something prior, and therefore no complex can be a first principle of demonstration. If it is incomplex, it is either that-which-it-is of the passion or of the subject, but not of the passion, for that-which-it-is of the passion is demonstrable and a first principle of demonstration is indemonstrable, therefore the first principle of a demonstration is not that-which-it-is of the passion. For it is necessary for a first complex to be resolved into a first incomplex, since it is necessary for such a resolution to occur in demonstration. Again, that-which-it-is of the subject cannot be demonstrated of that to which it belongs. The proof is since there is no demonstration of immediate things, but that-which-it-is of the subject is immediately in the subject, and therefore that-which-it-is of the subject cannot be demonstrated of the subject. Again, neither can it be demonstrated of another. The proof is that if it is, it will either be demonstrated of an accident or of a subject, and it cannot be demonstrated of an accident since the conclusion of a demonstration must not be accidental, but in itself, but if that-which-it-is of the subject were to be demonstrated of an accident, the conclusion of the demonstration would be accidental. This is said in Posterior Analytics I, because it is said to be accidental predication when the subject is predicated of an accident, as in saying “the white thing is a man,” for since what is naturally suited to be predicated is not predicated, nor is what is naturally suited to be a subject the subject, therefore etc. Again, neither is that-which-it-is demonstrated of a substance, since if it were, either it would be demonstrable of itself or of another. It is not demonstrated of itself, as has been shown, nor of another. The proof is that every predication of one substance of another that differs from it is impossible, but the conclusion of a demonstration is not impossible, therefore in the conclusion of a demonstration that-which-it-is of the subject cannot be demonstrated of a substance other than it in essence. Therefore it can be demonstrated neither of itself nor of any other.

            Therefore in no way is it demonstrable by demonstration without qualification; and this is what the Commentator contends on Metaphysics VI, where this matter is spoken of, for makes this argument there: demonstration is from substances to accidents, substance does not have a substance, therefore there is no demonstration of substance. These propositions seem unconnected, but when he says demonstration is from substances to accidents this suggests that that which is demonstrated is related to that of which it is demonstrated as accident to substance, from which this major premise is accepted: that which is demonstrated of another must be accidental to it, etc. But he says a substance does not have a substance, suggesting that a substance is not accidental to a substance. And this is put together with the first, and it is concluded that there is no demonstration of substance, so that that-which-it-is of a substance cannot be demonstrated without qualification.

            Nevertheless that-which-it-is of the subject can be demonstrated in a way, for a subject has two definitions, the material and the formal. The material definition is demonstrated through the formal definition, as the Philosopher contends in the text. And therefore similarly that-which-it-is of a subject considered according to matter can be demonstrated through that-which-it-is of the subject considered as form, and so that-which-it-is of the subject can in a way be demonstrated, since the material definition can be demonstrated through the formal definition. But it must be understood that when material definition is demonstrated it is not demonstrated through a definition composed of the formal and material definitions, since whoever demonstrates a material definition in this way begs the question, for he supposes in the minor premise what must be demonstrated. And therefore if it must be demonstrated it will be demonstrated through the formal definition. I claim the same thing of that-which-it-is of the subject, if it must be demonstrated, it will be demonstrated through that-which-it-is of the subject considered solely as form. And noting this, the Commentator on Metaphysics VI says that substances do not have demonstration which returns to the cause and being at the same time, that is to say, if that-which-it-is of the subject were demonstrated, the middle of demonstration would not collect into itself both cause and being, that is, both the material cause and the formal cause providing being, so it does not receive as its middle term a definition composed of the formal and material definitions. Therefore he says further on that substances do not have demonstrations that are rearranged definitions; that is, that-which-it-is of the subject, if it is demonstrated, is not demonstrated through the definition of the subject which is the whole demonstration, the position differing, but that-which-it-is of the subject is only demonstrated considered as matter through that-which-it-is of the subject considered as form, not through that-which-it-is put together from both. Briefly, then, it appears what is to be said when it is asked etc., since that-which-it-is of a passion can be demonstrated not of the passion but of the subject, but that-which-it-is of the subject cannot be demonstrated of that to which it belongs nor of any other, by formal demonstration.

            From this in response to the arguments, as for the first, when it is argued, “everything that has another as a cause” etc., if this proposition is taken to be perfectly general, it is false. For there is not anything other than the first that does not have another as a cause, no matter whether it be a corporeal or intellectual nature. It is true that every complex (i.e. proposition) that has another as a mediating cause between the subject and predicate can be demonstrated, but if the major premise is taken universally this is false. For everything other than the first has another as a cause, for there is one effective cause of all things, as Proclus proves. And in response to the minor premise, I hold that it is true. But it does not have another as effective cause of that-which-it-is, which is the mediating cause between subject and predicate. And therefore that-which-it-is is not demonstrated by demonstration without qualification. Now what is demonstrated is a conclusion, between the subject and predicate of which there is another acting as cause; but there is not another acting as cause of that-which-it-is with respect to that to which it belongs, and therefore the definition is in no way demonstrated without qualification of that to which it belongs, since a mediating cause does not fall between that-which-it-is and that to which it belongs. So Grosseteste says that demonstration makes us know the definition of the defined not insofar as it is definitive, stating that-which-it-is of that to which it belongs, but insofar as it is provable of the defined by a predication saying that this is this.

            In response to the other, when it is argued, “the conclusion of a demonstration can be demonstrated,” this is true. And you say “a definition” etc., this is true, and therefore it can be demonstrated. And you say, “that-which-it-is conveys through” etc., I reply that that-which-it-is considered according to form is conveyed by the formal definition. But that-which-it-is of the subject considered according to matter is conveyed by the material definition. And therefore I grant that just as a material definition can be demonstrated by a formal definition, so also that-which-it-is considered in the one way can be demonstrated by that-which-it-is considered in the other.

Question 61

            It is asked whether a that-which-it-is can be demonstrated or shown by division.

            And it is argued that it can, since that way which sufficiently lays hold of every essential predicate of the defined seems sufficiently to demonstrate its that-which-it-is. But division sufficiently lays hold of every essential predicate of the defined, as is said in the text. Therefore etc.

            Again, nothing more is required for obtaining a definition than sufficiently laying hold of every essential predicate, and a due ordering of the parts in the definition. But the first can occur through division, as is said in the text. Again, the second also, since one can lay hold of the genus first through division, and then more common differences until one arrives at something convertible with the defined. Therefore etc.

            The opposed view is clear from the Philosopher.

            It must be said in reply to this that one cannot sufficiently demonstrate that-which-it-is through division, since that argumentation that only infers something and does not prove it does not demonstrate that-which-it-is sufficiently. Every demonstration proves something sufficiently. Now division only infers something, and does not prove it. Therefore etc. The minor premise is apparent. For if it is argued thus, “every animal is rational or irrational, man is an animal, therefore man is rational or irrational,” up to here what is proposed is well concluded, as is said in Prior Analytics I. But when it is said next, “man is rational or irrational, and man is not irrational, therefore man is rational,” this begs the question, since the major premise is just as dubious as the conclusion, and when things are concluded in this way there is begging the question. But such an illation, although it infers, still does not prove, therefore etc. Through this same argument it can be shown that definition of definition, and that definition of the contrary, and that syllogism, does not sufficiently prove that-which-it-is. And therefore all of these can be quickly disposed of, for all of these way which were taught, when they were used to prove that that-which-it-is of that to which it belongs, ask for that-which-it-is of in the beginning; therefore they are absurd.

            But although the way of syllogism and the way of division do not adequately demonstrate that-which-it-is, they contribute to investigating that-which-it-is, and this is what the Commentator contends on Metaphysics VI, that the definitions of substances arise these four ways: by the senses, by syllogism, by composition, and by division. So a way sufficient for investigating definition and that-which-it-is is composed from these four. Although the Commentator on De Anima I does not make mention there of the two by syllogism and by composition, still that these contribute to the investigation of that-which-it-is is obvious, since if we wish to investigate that-which-it-is of man, we ought first to consider in what determinate genus man is found. Now it happens that man is in the genus of animal, and that man arises in this genus must be received from the senses and syllogism. That man is in the genus of animal is argued thus: everything that has sense and motion is in the genus of animal, for animal is distinguished from non-animal by sense and motion, but man has sense and motion; therefore etc. The minor premise must be received from sense. Next the genus of man, which is animal, must be divided through opposite differences, namely thorugh rational and irrational. There is a demonstration from the senses, as it happens, that man is contained under one of the dividing opposites, since it is under the rational. For everything that actually understands and feels is rational, man is like this, and this we have from the senses, therefore etc. Since, then, we have from the senses that man is contained under the rational, next this difference which man is under must be combined with the genus, and then we must see whether the difference together with the genus is convertible with man. If it is, we are done, for we have a definition; if not, we must divide that composite next, and in this way we are always to proceed until we arrive at an aggregate that is convertible with the defined. And so these four ways are required for the investigation of that-which-it-is and none of these is sufficient by itself. It is true that we can conclude a definition of the defined through division, but we still cannot conclude a definition of the defined insofar as it is a definition saying what it is, but in this way whoever wants to do this begs the question. Again, we cannot, without qualification, prove a definition of the defined, although we can infer it.

            In response to the arguments, as to the first, when it is said, “that way which sufficiently” etc., this is false. For the Philosopher says in Posterior Analytics II that divisions according to differences are useful for cognizing that-which-it-is, but they don’t demonstrate, and are only useful for collecting together that-which-it-is. That is, divisions are not useful for demonstrating the definition of the defined, but they are useful for collecting, and therefore division is no good for investigating that-which-it-is as an argument, but only as a way of collecting it together.

            In response to the other, I hold that it is true that no more is required to investigate this, but more would be required for it to be demonstrated.

Question 62

            We inquire concerning the part in which the Philosopher discusses the demonstrative middle, according to which he says “propter quid et causam”; namely, whether it is possible to demonstrate through a material cause.

            And it is argued that it is not, for it is not possible to demonstrate something through what is neither a principle of being nor of cognizing, but a material cause is not a principle of being, rather form only is. Again, neither is it a principle of cognizing, but a hindrance to cognition, as the Commentator says on Physics I. Therefore etc.

            Again, it is not possible to demonstrate something, at least not without qualification, through what does not have the form of a cause. But matter does not seem to have the form of a cause, for from a cause something flows to the thing caused, but nothing flows from matter to the thing caused, for this belongs to perfection, and no perfection belongs to matter. Therefore etc.

            On the other hand, it is argued that it is possible to demonstrate through that from which necessity arises in natural things, for otherwise natural demonstrations would not be demonstrations; but necessity in natural things does not arise from matter, as is said in Physics II; therefore etc.

            It must be replied to this that it is possible to demonstrate through a material cause, for it is possible to demonstrate through that from which one shows something to follow of necessity. Now something follows of necessity from a material cause, as is said in the text. Therefore etc.

            Again, this is obvious since nature and form are causes intrinsic to a thing. But a cause is that upon the being of which another follows of necessity. Therefore from a material cause something follows of necessity. Then it is argued that through that from which something can follow of necessity something can be demonstrated, but a material cause is like this, as is clear from the form of cause; therefore etc.

            But it must be noted that matter can be considered in two ways, either according to the nature of matter itself or as it is subject to active and passive qualities. Considering matter in the first way, it is not active toward any effect, nor is it a productive cause of any effect. For each acts and produces as it is in act, but matter in its nature does not have any act; therefore etc. Nor can anything be demonstrated through a material cause in this way, for in this way it has no essential concept through which it is understood by us in its essence and nature; for it is understood only by analogy to form. But if matter be considered in the second way it is a cause of some effect, and so through this something can be demonstrated, for it is matter as it is subject to active and passive qualities and as such it is a principle for demonstrating something, namely, that something is corruptible, thus: Every composite of contraries is corruptible, but this is of that sort something is demonstrated; therefore etc.

            Again, if through matter we understand the parts of some whole, for these are related to the whole in form of matter, in this way it is possible to demonstrate something through matter, since it is possible to demonstrate something about a whole though the parts of the whole. So through the vibratory motion which is in the head it is possible to demonstrate that vibratory motion is in the whole; nor does it seem possible to demonstrate through the material cause in any other way than through parts, and this is how the examples of the Philosopher sound.

            In response to the arguments: as to the first, when it is argued, “through what is neither a principle” etc., it is true in this way, and you say “matter” etc., which is true as it is considered absolutely, but only form is a principle of being and cognizing; but matter as a subject of active and passive qualities, or also as parts are called matter, is a principle of being and cognizing.

            And it is apparent how to respond to the second argument from the same considerations.