Part I (Prima Pars) Part 129 (1/2)
Obj. 2: Further, the intellectual soul is more excellent than corporeal primary matter. But primary matter was created by G.o.d under the forms to which it has potentiality. Therefore much more is the intellectual soul created by G.o.d under intelligible species. And so the soul understands corporeal things through innate species.
Obj. 3: Further, no one can answer the truth except concerning what he knows. But even a person untaught and devoid of acquired knowledge, answers the truth to every question if put to him in orderly fas.h.i.+on, as we find related in the Meno (xv seqq.) of Plato, concerning a certain individual. Therefore we have some knowledge of things even before we acquire knowledge; which would not be the case unless we had innate species. Therefore the soul understands corporeal things through innate species.
_On the contrary,_ The Philosopher, speaking of the intellect, says (De Anima iii, 4) that it is like ”a tablet on which nothing is written.”
_I answer that,_ Since form is the principle of action, a thing must be related to the form which is the principle of an action, as it is to that action: for instance, if upward motion is from lightness, then that which only potentially moves upwards must needs be only potentially light, but that which actually moves upwards must needs be actually light. Now we observe that man sometimes is only a potential knower, both as to sense and as to intellect. And he is reduced from such potentiality to act--through the action of sensible objects on his senses, to the act of sensation--by instruction or discovery, to the act of understanding. Wherefore we must say that the cognitive soul is in potentiality both to the images which are the principles of sensing, and to those which are the principles of understanding. For this reason Aristotle (De Anima iii, 4) held that the intellect by which the soul understands has no innate species, but is at first in potentiality to all such species.
But since that which has a form actually, is sometimes unable to act according to that form on account of some hindrance, as a light thing may be hindered from moving upwards; for this reason did Plato hold that naturally man's intellect is filled with all intelligible species, but that, by being united to the body, it is hindered from the realization of its act. But this seems to be unreasonable. First, because, if the soul has a natural knowledge of all things, it seems impossible for the soul so far to forget the existence of such knowledge as not to know itself to be possessed thereof: for no man forgets what he knows naturally; that, for instance, the whole is larger than the part, and such like. And especially unreasonable does this seem if we suppose that it is natural to the soul to be united to the body, as we have established above ([Q. 76] , A. 1): for it is unreasonable that the natural operation of a thing be totally hindered by that which belongs to it naturally. Secondly, the falseness of this opinion is clearly proved from the fact that if a sense be wanting, the knowledge of what is apprehended through that sense is wanting also: for instance, a man who is born blind can have no knowledge of colors. This would not be the case if the soul had innate images of all intelligible things. We must therefore conclude that the soul does not know corporeal things through innate species.
Reply Obj. 1: Man indeed has intelligence in common with the angels, but not in the same degree of perfection: just as the lower grades of bodies, which merely exist, according to Gregory (Homily on Ascension, xxix In Ev.), have not the same degree of perfection as the higher bodies. For the matter of the lower bodies is not totally completed by its form, but is in potentiality to forms which it has not: whereas the matter of heavenly bodies is totally completed by its form, so that it is not in potentiality to any other form, as we have said above (Q. 66, A. 2). In the same way the angelic intellect is perfected by intelligible species, in accordance with its nature; whereas the human intellect is in potentiality to such species.
Reply Obj. 2: Primary matter has substantial being through its form, consequently it had need to be created under some form: else it would not be in act. But when once it exists under one form it is in potentiality to others. On the other hand, the intellect does not receive substantial being through the intelligible species; and therefore there is no comparison.
Reply Obj. 3: If questions be put in an orderly fas.h.i.+on they proceed from universal self-evident principles to what is particular. Now by such a process knowledge is produced in the mind of the learner.
Wherefore when he answers the truth to a subsequent question, this is not because he had knowledge previously, but because he thus learns for the first time. For it matters not whether the teacher proceed from universal principles to conclusions by questioning or by a.s.serting; for in either case the mind of the listener is a.s.sured of what follows by that which preceded.
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FOURTH ARTICLE [I, Q. 84, Art. 4]
Whether the Intelligible Species Are Derived by the Soul from Certain Separate Forms?
Objection 1: It would seem that the intelligible species are derived by the soul from some separate forms. For whatever is such by partic.i.p.ation is caused by what is such essentially; for instance, that which is on fire is reduced to fire as the cause thereof. But the intellectual soul forasmuch as it is actually understanding, partic.i.p.ates the thing understood: for, in a way, the intellect in act is the thing understood in act. Therefore what in itself and in its essence is understood in act, is the cause that the intellectual soul actually understands. Now that which in its essence is actually understood is a form existing without matter. Therefore the intelligible species, by which the soul understands, are caused by some separate forms.
Obj. 2: Further, the intelligible is to the intellect, as the sensible is to the sense. But the sensible species which are in the senses, and by which we sense, are caused by the sensible object which exists actually outside the soul. Therefore the intelligible species, by which our intellect understands, are caused by some things actually intelligible, existing outside the soul. But these can be nothing else than forms separate from matter. Therefore the intelligible forms of our intellect are derived from some separate substances.
Obj. 3: Further, whatever is in potentiality is reduced to act by something actual. If, therefore, our intellect, previously in potentiality, afterwards actually understands, this must needs be caused by some intellect which is always in act. But this is a separate intellect. Therefore the intelligible species, by which we actually understand, are caused by some separate substances.
_On the contrary,_ If this were true we should not need the senses in order to understand. And this is proved to be false especially from the fact that if a man be wanting in a sense, he cannot have any knowledge of the sensibles corresponding to that sense.
_I answer that,_ Some have held that the intelligible species of our intellect are derived from certain separate forms or substances. And this in two ways. For Plato, as we have said (A. 1), held that the forms of sensible things subsist by themselves without matter; for instance, the form of a man which he called _per se_ man, and the form or idea of a horse which is called _per se_ horse, and so forth.
He said therefore that these forms are partic.i.p.ated both by our soul and by corporeal matter; by our soul, to the effect of knowledge thereof, and by corporeal matter to the effect of existence: so that, just as corporeal matter by partic.i.p.ating the idea of a stone, becomes an individuating stone, so our intellect, by partic.i.p.ating the idea of a stone, is made to understand a stone. Now partic.i.p.ation of an idea takes place by some image of the idea in the partic.i.p.ator, just as a model is partic.i.p.ated by a copy. So just as he held that the sensible forms, which are in corporeal matter, are derived from the ideas as certain images thereof: so he held that the intelligible species of our intellect are images of the ideas, derived therefrom.
And for this reason, as we have said above (A. 1), he referred sciences and definitions to those ideas.
But since it is contrary to the nature of sensible things that their forms should subsist without matter, as Aristotle proves in many ways (Metaph. vi), Avicenna (De Anima v) setting this opinion aside, held that the intelligible species of all sensible things, instead of subsisting in themselves without matter, pre-exist immaterially in the separate intellects: from the first of which, said he, such species are derived by a second, and so on to the last separate intellect which he called the ”active intelligence,” from which, according to him, intelligible species flow into our souls, and sensible species into corporeal matter. And so Avicenna agrees with Plato in this, that the intelligible species of our intellect are derived from certain separate forms; but these Plato held to subsist of themselves, while Avicenna placed them in the ”active intelligence.” They differ, too, in this respect, that Avicenna held that the intelligible species do not remain in our intellect after it has ceased actually to understand, and that it needs to turn (to the active intellect) in order to receive them anew. Consequently he does not hold that the soul has innate knowledge, as Plato, who held that the partic.i.p.ated ideas remain immovably in the soul.
But in this opinion no sufficient reason can be a.s.signed for the soul being united to the body. For it cannot be said that the intellectual soul is united to the body for the sake of the body: for neither is form for the sake of matter, nor is the mover for the sake of the moved, but rather the reverse. Especially does the body seem necessary to the intellectual soul, for the latter's proper operation which is to understand: since as to its being the soul does not depend on the body. But if the soul by its very nature had an inborn apt.i.tude for receiving intelligible species through the influence of only certain separate principles, and were not to receive them from the senses, it would not need the body in order to understand: wherefore to no purpose would it be united to the body.
But if it be said that our soul needs the senses in order to understand, through being in some way awakened by them to the consideration of those things, the intelligible species of which it receives from the separate principles: even this seems an insufficient explanation. For this awakening does not seem necessary to the soul, except in as far as it is overcome by sluggishness, as the Platonists expressed it, and by forgetfulness, through its union with the body: and thus the senses would be of no use to the intellectual soul except for the purpose of removing the obstacle which the soul encounters through its union with the body. Consequently the reason of the union of the soul with the body still remains to be sought.
And if it be said with Avicenna, that the senses are necessary to the soul, because by them it is aroused to turn to the ”active intelligence” from which it receives the species: neither is this a sufficient explanation. Because if it is natural for the soul to understand through species derived from the ”active intelligence,”
it follows that at times the soul of an individual wanting in one of the senses can turn to the active intelligence, either from the inclination of its very nature, or through being roused by another sense, to the effect of receiving the intelligible species of which the corresponding sensible species are wanting. And thus a man born blind could have knowledge of colors; which is clearly untrue. We must therefore conclude that the intelligible species, by which our soul understands, are not derived from separate forms.
Reply Obj. 1: The intelligible species which are partic.i.p.ated by our intellect are reduced, as to their first cause, to a first principle which is by its essence intelligible--namely, G.o.d. But they proceed from that principle by means of the sensible forms and material things, from which we gather knowledge, as Dionysius says (Div. Nom.
vii).
Reply Obj. 2: Material things, as to the being which they have outside the soul, may be actually sensible, but not actually intelligible. Wherefore there is no comparison between sense and intellect.
Reply Obj. 3: Our pa.s.sive intellect is reduced from potentiality to act by some being in act, that is, by the active intellect, which is a power of the soul, as we have said (Q. 79, A. 4); and not by a separate intelligence, as proximate cause, although perchance as remote cause.
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FIFTH ARTICLE [I, Q. 84, Art. 5]