CHAPTER V
CHAPTER V
[99] Arguments intended to exclude a plurality of possible intellects remain to be dealt with. The first is this: Whatever is multiplied by a division of matter is a material form, which is why substances separate from matter cannot be many members of the same species. If then there were a plurality of intellects in many men who are numerically distinguished from one another by the division of matter, it would necessarily follow that intellect is a material form. But that goes against the words of Aristotle and the argument in which he proves the intellect is separate. If then it is separate it is not a material form and can in no way be multiplied according to the multiplication of bodies.
[100] So attached are they to this argument that they say God could not make many intellects of the same species in diverse men, because, they say, this would imply a contradiction: to have a nature that can be numerically multiplied is other than the nature of separated form. They go beyond this, however, and want to conclude from this that no separate form is numerically one nor an individuated thing. They say this is apparent from the word itself, for only that is numerically one which is one of a number of thingss, but form freed from matter is not one of a number because it does not have within it the cause of number, which is matter.
[101] To begin at the end, they seem not to understand their own words in what was just said. For Aristotle, in Book Four of the Metaphysics, says that “the essence of each thing is one in no merely accidental way” and that “similarly it is from its very nature something that is.” If separated substance is being, therefore, it must be one substance, especially since Aristotle says in Book Eight of the Metaphysics that things which have no matter have no cause of their being or of their being one. In Book Five of the Metaphysics, four kinds of unity are distinguished, namely, numeric, specific, generic and proportional. It cannot be said that any separate substance is one only specifically or generically, since this is not to be one simply speaking. There remains that a separate substance is numerically one. Nor is it said to be numerically one because it is one among numbers—number is not the cause of the one but vice versa—but because in numbering it is not divided: one is that which is undivided.
[102] Nor is it true to say that every number is caused by matter, for then Aristotle would have inquired in vain after the number of separated substances. For Aristotle says in Book Five of the Metaphysics that “many” is said not only numerically but specifically and generically. Nor is it true that separate substance is not singular and individuated, otherwise it would have no operation, since acts belong only to singulars, as the Philosopher says; hence he argues against Plato in Book Seven of the Metaphysics that if the Idea is separate, it will not be predicated of many, nor will it be definable any more than other individuals which are unique in their species, like the sun and moon. Matter is the principle of individuation in material things insofar as matter is not shareable by many, since it is the first subject not existing in another. Hence Aristotle says that if the Idea were separate “it would be something, that is, an individual, which it would be impossible to predicate of many.”
[103] Separate substances, therefore, are individual and singular, but they are individuated not by matter but by this that it is not their nature to exist in another and consequently to be participated in by many. From which it follows that if any form is of a nature to be participated in by something, such that it be the act of some matter, it can be individuated and multiplied by comparison with matter. It has already been shown above that the intellect is a power of the soul which is the act of the body. Therefore in many bodies there are many souls and in many souls there are many intellectual powers, that is, intellects. Nor does it follow from this that the intellect is a material power, as has been shown.
[104] Should anyone object that, if the many souls are multiplied according to bodies, it follows that they will not remain when the bodies have been destroyed, the response is obvious from what has already been said. A thing is one in the way it is a being, as is said in Book Four of the Metaphysics; therefore, for the soul to be is to be in the body as its form, nor is it prior to body, nonetheless it remains in existence after the body is destroyed: thus each soul remains in its unity and consequently many souls in their manyness.
[105] They argue most crudely to show that God cannot bring it about that there should be many intellects, believing this to involve a contradiction. For even granting that it is not of the nature of intellect that it be multiplied, it does not follow from this that the multiplying of intellect involves a contradiction. Nothing prevents a thing’s getting from another something that it is not of its nature to have: it is not of the nature of the heavy to be above, yet for the heavy to be above does not involve a contradiction although for the heavy to be above by its very nature would involve a contradiction. Thus if the intellect were naturally one for all because it had no natural cause of multiplication, multiplication could nonetheless come about through a supernatural cause without involving any contradiction. We say this not because of the present question but lest this form of arguing be extended to other cases, for in this way one could conclude that God cannot bring it about that the dead should rise and the blind have their sight restored to them.
[106] To bolster their error they bring forth another argument. They ask whether what is understood in me and in you is completely one or numerically two but specifically one. If what is understood is one, there will be one intellect. If numerically two but specifically one, it follows that they will have as things understood the thing understood. Wherever there are numerically two but specifically one there is one thing understood, because there is one quiddity through which understanding takes place, and thus to infinity, which is impossible. Therefore it is impossible that there be numerically two things understood in me and you. There is one alone, then, and numerically only one intellect in all.
[107] It ought to be asked by those who consider themselves to argue so subtly whether for things understood to be numerically two but specifically one is contrary to the notion of the understood insofar as it is understood, or insofar as it is understood by man. It is clear from the argument they formulate that it is contrary to the notion of the thing understood. For it is of the notion of the thing understood as such that nothing need be abstracted from it in order that it be understood. Therefore, on the basis of their argument, we can conclude, not just that there is only one thing understood by all men, but that there is simply one thing understood. And if there is but one thing understood, on their reasoning it follows that there is only one intellect in the whole world, not only for men. Therefore not only is our intellect a separate substance, it is also God Himself, and the plurality of separated substances is wholly swept away.
[108] One who sought to respond that the thing understood by one separate substance and that understood by another are not specifically one because the intellects differ specifically, would deceive himself because that which is understood is related to understanding and to intellect as an object to act and potency. The object does not take its species from either the act or the power, but rather the other way around. Therefore it must simply be conceded that the understanding of one thing, say a stone, is one alone not only in all men but also in all intelligences.
[109] But it remains to ask what is the understood itself. For if they say that the thing understood is one immaterial species existing in the intellect, in a way they unwittingly slide into the teaching of Plato who taught that there can be no science of sensible things, but every science is of one separated form. It is not relevant whether someone says that the knowledge of a rock is of one separated form of rock or of one form of rock that is in the intellect. In either case it follows that sciences are not of the things that are here, but only of separated things. Because Plato taught that immaterial forms of this kind are of themselves subsistent, he could maintain along with this that many intellects derive from one separate form knowledge of one truth. But those who posit immaterial forms of this kind—which they call the things understood—in the intellect, have to say that there is only one intellect, not only for all men, but absolutely speaking.
[110] In keeping with the teaching of Aristotle, therefore, it ought to be said that the understood thing which is one is the very nature or quiddity of the thing: natural science and the other sciences are of things, not of understood species. For if the thing understood were not the very nature of rock which is in things, but the species which is in the intellect, it would follow that I do not understand the thing that is a stone, but only the intention which is abstracted from the stone. It is true that the nature of stone as it is in singulars is only potentially understood, but it comes to be actually understood because the species come from sensible things, through the mediation of the senses, to imagination, from which the intelligible species which are in the possible intellect are abstracted by the power of the agent intellect. These species, however, do not relate to possible intellect as what is understood, but as species through which the intellect understands, just as the species which are in sight are not the things seen, but that whereby sight sees, save insofar as the intellect reflects upon itself, which cannot happen in the case of sense.
[111] If however understanding were a transitive action passing into exterior matter, like burning and moving, it would follow that understanding exists in the way the nature of things exists in singulars just as the combustion of fire exists according to the manner of the combustible. But because understanding is an action which remains in the one understanding, as Aristotle says in Book Nine of the Metaphysics, it follows that understanding is according to the mode of the one understanding, that is, according to the demands of the species whereby the understander understands. But this, since it is abstracted from individual principles, does not represent the thing in its individual conditions but only according to the universal nature. If two are conjoined in a thing, nothing prevents one of them being represented in sense without the other: hence the color of honey or of the apple is seen by sight without its taste. Just so the intellect understands the universal nature by abstraction from individual principles.
[112] Therefore there is one thing that is understood by me and you, but it is understood by means of one thing by me and by means of another by you, that is, by different intelligible species, and my understanding differs from yours and my intellect differs from yours. Hence Aristotle in the Categories says that knowledge is singular with respect to its subject, “the individual knowledge of grammar is in a subject, the soul, but is not said of any subject.” Hence when my intellect understands itself to understand, it understands some singular activity; when however it understands understanding simply, it understands something universal. It is not singularity that is repugnant to intelligibility, but materiality; thus, since they are immaterial singulars, as was said of separate substances above, nothing prevents such singulars from being understood.
[113] Thus it is clear how there can be the same science in the learner and teacher. For it is the same with respect to the thing known, but not with respect to the intelligible species whereby each knows—in that respect, science is individuated in me and you. Nor is it necessary that the knowledge which is in the learner be caused by the knowledge that is in the teacher as the heat of water by the heat of fire, but as the health in matter is caused by the health that is in the mind of the physician. Just as in the patient there is a natural principle of health to which the physician supplies aids in order that health might be perfected, so in the learner there is a natural principle of knowledge, namely the agent intellect and the first self-evident principles. The teacher supplies certain aids, deducing conclusions from principles known in themselves. Thus the physician strives to heal in the way nature would heal, namely, by heating and chilling; similarly the master leads to science in the way in which one discovering it for himself would acquire it, proceeding, that is, from the known to the unknown. And just as health in the sick person does not come about by the power of the physician but by the capacity of nature, so too knowledge is not caused in the learner by the power of the master, but by the capacity of the learner.
[114] As to the further objection that if, their bodies having been destroyed, many intellectual substances should remain, it would follow that they are otiose, since Aristotle in Book XI of the Metaphysics argued that if there were separated substances which did not move bodies, they would be otiose. But if one carefully considers the text of Aristotle, the difficulty is easily solved. For Aristotle, before giving this argument, says, “the unmovable substances and principles may reasonably be taken to be just so many; the assertion of necessity must be left to more powerful thinkers.” It is clear from this that he is pursuing a kind of probability and not claiming necessity.
[115] Since that is otiose which does not attain the end for which it is designed, they cannot say even with probability that the separated substances are otiose if they do not move bodies, unless perhaps they mean that the motions of bodies are the ends of separated substances, which is completely impossible, since the end is higher than the things that are for the sake of the end. Nor does Aristotle here conclude that they would be otiose if they did not move bodies, but that “every being and every substance which is immune from change and in virtue of itself has attained to the best must be considered an end.” It is the most perfect state of any thing that it not only is good in itself, but also causes goodness in others. But it was not clear how separated substances would cause goodness in inferior bodies save by the motion of some bodies, hence Aristotle derived from this a probable argument to show that there are as many separate substances as are manifested by the heavenly bodies, although as he himself says this has no claim to necessity.
[116] We concede that the human soul separated from body does not have the ultimate perfection of its nature, since it is a part of human nature: no part has complete perfection if it is separated from its whole. But it is not for this reason frustrated, for the end of the human soul is not to move the body, but to understand, in which its happiness consists, as Aristotle proves in Book Ten of the Ethics.
[117] In advancing their error they also say that if there were many intellects for many men, since intellect is incorruptible, it would follow on Aristotle’s view, since he held the world to be eternal and men to have always existed, that there would be an actual infinity of intellects. Algazel responded to this in his Metaphysics saying that “in anything where there is one of these without the other,” that is, quantity or a multitude without order, “infinity will not be taken from it, as in the case of the movement of the heaven.” And later he adds, “Similarly we grant that human souls, which are separable from the body at death, are infinite in number, although they exist at the same time, since there is no natural ordering among them by the removal of which souls would cease to exist; none of them is the cause of the others, but in nature and position they are simultaneously without prior and posterior. There is no prior and posterior in them according to nature save according to the time of their creation. In their essences insofar as they are essences there is no ordering in any way, but they are equal in existence, unlike spaces and bodies and cause and effect.”
[118] We cannot know what Aristotle’s solution to this might have been because we don’t possess that part of the Metaphysics in which he deals with separated substances. In Book Two of the Physics the Philosopher says that of the forms “the mode of existence of the separable” insofar as they are separable, “it is the business of first philosophy to define.” But it is obvious that whatever he says about this would cause no distress to Catholics, who hold that the world began.
[119] They speak falsehood who say that it was a principle with all those who philosophize, both Arabs and Peripatetics, if not for the Latins, that the intellect is not multiplied numerically. Algazel was an Arab, not a Latin. And Avicenna too, who was an Arab, speaks thus in his book On the Soul, “Prudence, stupidity, opinion can only inhere in the essence of the soul. Therefore the soul is not numerically one but many though of one species.”
[120] And lest we omit the Greeks, we should cite the words of Themistius in his commentary. For when he asked of the agent intellect whether it was one or many, he answered: “Or the first illuminator is one but the illumined and illumining many: for the sun is one, but you will say that light is in some way imparted to sight. For this reason Aristotle proposes light rather than the sun in the comparison, but Plato proposes the sun.” It is clear from these words of Themistius that neither the agent intellect, of which Aristotle speaks, is the one who is illuminator, nor the possible that which is illumined. There is indeed one principle of illumination, namely a certain separated substance which is either God, according to Catholics, or the ultimate intelligence according to Avicenna. Themistius proves the unity of this separate principle by the fact that the teacher and learner understand the same thing, which would not be the case if there were not the same illuminating principle. What he says later, that some doubt whether the possible intellect is one, is certainly true.
[121] But he says no more of this because his intention was not to discuss the diverse opinions of philosophers, but to explicate the teachings of Aristotle, Plato and Theophrastus. Hence at the end he concludes, “What I said to express what seemed to philosophers to be the case is of singular difficulty and concern. From what I have said one can gather the views of Aristotle and Theophrastus, and especially of Plato, about them.” It is evident, therefore, that Aristotle and Theophrastus and Themisitius and Plato himself did not hold as a principle that the possible intellect is one for all. Averroes, it is clear, distorts in reporting it the thought of Themistius and Theophrastus concerning possible and agent intellects, so we rightly said above that he is the perverter of Peripatetic philosophy. How wonderful then that some, consulting only the commentary of Averroes, presume to pronounce that what he says is the common view of all philosophers, Greek and Arab, if not the Latins.
[122] It is yet more wonderful, indeed worthy of indignation, that anyone professing himself to be a Christian should presume to speak so irreverently of the Christian faith as to say that, “The Latins do not accept this as a principle,” namely, that there is only one intellect, “perhaps because their law is contrary to it.” There are two evils in this. First, to doubt whether this is against the faith; second, to give the nod to what is alien to this law. Afterward he said, “This is the reason why Catholics seem to hold their position,” where the judgment of the faith is called a position! Nor is there less presumption in what he dares later to assert, namely that God cannot bring it about that there are many intellects, because this implies a contradiction.
[123] Even more serious is this subsequent remark: “Through reason I conclude necessarily that intellect is numerically one, but I firmly hold the opposite by faith.” Therefore he thinks faith is of things whose contrary can be necessarily concluded; since the only thing that can be necessarily concluded is a necessary truth whose opposite is false and impossible, it follows from this statement that faith is of the false and impossible, which not even God can bring about and the ears of the faithful cannot bear. He does not lack the high temerity to presume to discuss what does not pertain to philosophy but is purely of faith, such that the soul suffers from the fire of hell, and to say that the teaching of the doctors concerning these things should be reprobated. By equal right one could dispute concerning the Trinity, the Incarnation and the like, concerning which he speaks only in ignorance.
[124] This then is what we have written to destroy the error mentioned, using the arguments and teachings of the philosophers themselves, not the documents of faith. If anyone glorying in the name of false science wishes to say anything in reply to what we have written, let him not speak in corners nor to boys who cannot judge of such arduous matters, but reply to this in writing, if he dares. He will find that not only I, who am the least of men, but many others zealous for the truth, will resist his error and correct his ignorance.