I have skipped objections and abbreviated each paragraph within the corpus, restating most in my words.
Q 84* resumed:
"Early philosophers" (pre-Socratics) were sceptics because materialists. Body all there is, and in a flux.
Plato answered we know ideas, "by participation of which each one of those singular things is said to be man or horse or the like" but not bodies of which they are ideas.
This is false, movement and matter are objects of science and the material things are manifest. Plato thought the form of the thing known must be in outside reality in same manner as in human mind, but our ideas idealise in a way not corresponding to what we observe of reality around us. Whiteness can - when observed rather than when we think of it as such - be of different intensity. Knowledge is received in the mode of the receiver and therefore ideas of mobile things as immobile ideas.
"Ancient philosophers" (pre-Socratics) considered we know things - bodily things - through the essence of our soul. Plato observed our soul is of immaterial nature and thought the forms of things (which we know) subsist immaterially (proven by the fact we, with immaterial minds, know them). But pre-Socratics thought known objects exist materially within the soul. They thought it must have same nature as most basic element, or it would not be able to mold itself to those different forms. And if Empedocles believed there are four elements plus attraction and repulsion, he concludes our soul is made of those too.
Aristotle argued against Empedocles that in that case one would need to have not just the material principles but indeed the results of them in the soul to known them, bone to know bones, flesh to know flesh, and so on. And if the soul knows fire because it is fire, so also the fire outside the soul would need to know fire.
But then we can avoid this only by saying material things exist IM-materially in the knowing soul. The material component of anything known stays outside the soul, it is through the immaterial component (of something - us or it) we know it. Things that accept forms only materially cannot know them. Senses give us the forms without the matter of the objects, intellect gives us the forms without even individuating circumstances of the matter. Among senses sight is most perfect since least material, among intellects that which is least material is most perfect.
The pre-Socratics were in a way right to think what knows a thing must include the principles of which they are an effect, but only insofar as that applies to Divine Knowledge, it is totally off the hook when applied to human knowledge since we are not the Creator. It is even wrong about angels.
Form is principle of action and something only potentially performing the action only potentially has the form. This means the species with which we might know things are not innate, what is innate is only the potentiality to all of them.
Of course an action can be hindered, and Plato thought we have actual species in us which are hindered by forgetfulness. But I cannot believe one can forget what one knows by the fact of having for nature to know it, and men born blind have no concept of colour.
Some have held that the species of our intellect or concepts of our understanding are derived from separate forms, in two ways. For Plato there was a thing like "man in himself" or "horse in itself" which subsisted without matter, and that these forms were on the one hand shared by matter (in each instance of "this man" or "this horse") and on the other hand by our soul. They gave existance to the "this one" and "that one" as well as knowledge to our soul. When matter participates the form "stone" it does so in becoming an individual stone, when soul participates the same for stone, it does so in starting to understand stone. The idea of participation can be understood as the relation of copy to original.
Aristotle proves in many ways the selfcontradiction of forms of material things subsisting without matter, so Avicenna says the immaterial forms pre-exist in each intellect. The ultimate one being "active intelligence" from which the species flow both into our souls (as understandable concepts) and into matter (as sensible images).
St Thomas answer Avicenna "if the soul by its very nature had an inborn aptitude 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."
Platonists would consider the senses (and species as images) as giving occasions to wake up to the ideal knowledge (where species are concepts), but the problem here is that if so the souls from senses only receives partial compensation for being united to the body at all, since that union was thought to cause the forgetfulness.
We cannot agree with Avicenna that by senses we ar aroused to turn to the active intellect, a man born blind cannot by hearing (or by its own nature for that matter) be turned to the active intellect and there come to know colours.
Next article St Thomas turns to St Augustine as source of a Platonism purified of errors, he cites De Doctrina Christiana ii:11 for the principle.
"If those who are called philosophers said by chance anything that was true and consistent with our faith, we must claim it from them as from unjust possessors. For some of the doctrines of the heathens are spurious imitations or superstitious inventions, which we must be careful to avoid when we renounce the society of the heathens."
The big difference is that instead of attributing creative and illuminative action to disembodied ideas of bodily things, he attributes the creative and illuminative action to God and says the disembodied ideas are ideas in God's mind.
Now, the Souls of the Blessed can look directly at the Eternal Types in God's mind and in that way know things in their eternal types. We on earth cannot, but we can see our senses in the light of the eternal types. How exactly?
Democritus did not distinguish between knowledge and sense and considered that knowledge occurs by a discharge of images.
Plato held that when sense impressions touch sense organs, these provoke in the soul sensual images which in their turn provoke the knowledge of eternal species.
Aristotle agreed much, but thought that sense perception belonged to body and soul at the same time. And Aristotle considered unlike Democritus that the objects caused this by some kind of operation. But activity is nobler than passivity and soul nobler than body. So, soul cannot be directly passive receiver of the action of sensible objects as if that sufficed, it also - itself - abstracts from them sense images to make of them understandable concepts. "According to this opinion, then, on the part of the phantasms, intellectual knowledge is caused by the senses. But since the phantasms cannot of themselves affect the passive intellect, and require to be made actually intelligible by the active intellect, it cannot be said that sensible knowledge is the total and perfect cause of intellectual knowledge, but rather that it is in a way the material cause."
As long as we live in our bodies, our soul needs phantasms of sense imagery to be engaged in actually understanding something.
First impaired brain function impairs understanding. The pure concepts need no brain, but we cannot directly access them without phantasms that do.
Second whenever we struggle to understand anything we make a construct of phantasms (sense imagery not concomitant to actual seeing or hearing etc.). "For this reason it is that when we wish to help someone to understand something, we lay examples before him, from which he forms phantasms for the purpose of understanding."
The power of knowledge "is proportioned to the thing known. Wherefore the proper object of the angelic intellect, which is entirely separate from a body, is an intelligible substance separate from a body. Whereas the proper object of the human intellect, which is united to a body, is a quiddity or nature existing in corporeal matter; and through such natures of visible things it rises to a certain knowledge of things invisible." And of course the visible things exist individually and therefore materially (St Thomas considered "matter" rather than "thisness" to be the principle of individuation, therein differring from Duns Scotus and from Bishop Tempier).
In the present life we cannot know things perfectly while our powers of sense are suspended, because the object of our knowledge here is incomplete without the sensual part. So, a suspension of senses implies a suspension of the correct judgement of the intellect.
So far Aquinas! One problem is his reason against Plato. Or part of it:
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 (76, 1): for it is unreasonable that the natural operation of a thing be totally hindered by that which belongs to it naturally.
From "And especially unreasonable does this seem if we suppose that it is natural to the soul to be united to the body", I have no objection. But as to impossibility of forgetting, what it is natural to know, well, I suppose he had never seen party hypnosis. But I totally agree that it is natural for the soul to be united to the body, and also for the soul to understand, so it cannot be a hindrance for the soul's understanding to be united to the body.
Or to have one's body placed where it is natural for the body to live, like on earth.
Bpi, Georges Pompidou
St Baudemer de Lyon
PS, when it comes to blind born men having no concept of colour, that seems to have been proven wrong since then. Karl May could imagine colour before an operation (in the childhood) gave him the eyesight he had never enjoyed before./HGL
* This resumé is based on:
New Advent site > Summa Theologica > First Part > Question 84
How the soul while united to the body understands corporeal things beneath it