Some internet links
Aquinas on human knowing:
Sensation as the proper source for embodied cognition.
sensation
common sense
imagination (phantasia: what are phantasms?)
cogitation (this is the estimative power in humans as rational)
memory
intellectual memory
The soul is form of the body, a doctrine fully developed by Aquinas.
Intellect is an immaterial power of soul.
Agent intellect is the power of abstraction.
Possible intellect is the power of reception of abstracted intelligible species (forms)
What is an intelligible species?
What is an intelligible in act?
What is a universal and how is it formed?
Thomas Aquinas, Summa theologiae, Prima Pars, Q79 A4, response:
I respond: The active intellect of which the Philosopher speaks is something that belongs to the soul. To see this clearly, note that beyond the human intellective soul it is necessary to posit a higher intellect from which the soul obtains its power to engage in intellective understanding. For it is always the case that what participates in something and is changeable and imperfect requires prior to itself something that is such-and-such through its essence, unchangeable, and perfect. But the human soul is called ‘intellective’ through participation in an intellectual power. An indication of this is that the human soul is intellective not as a whole, but rather with respect to a part of itself. Moreover, it arrives at an intellective understanding of truth discursively and through a movement, by way of argument. Again, it has imperfect intellective understanding, both because it does not understand all things and also because in the case of those things that it does understand, it proceeds from potentiality to actuality. Therefore, there must be some higher intellect by which the soul is assisted in engaging in intellective cognition. Thus, some have claimed that it is this intellect, separated with respect to its substance, which is the active intellect and which, by illuminating the phantasms, renders things actually intelligible.
However, granted that there is some such separated active intellect, it is nonetheless still necessary to posit within the human soul itself a power which is a participation in that higher intellect and through which the human soul renders things actually intelligible. As in the case of other perfect natural entities, there are, in addition to the universal agent causes, proper powers that are derived from the universal agents and given to individual perfect things. For instance, it is not the sun alone that generates a man; rather, there is in man a power to generate man—and the same holds for the other perfect animals. But among lower things there is none more perfect than the human soul. Hence, one must claim that within the human soul there is a power, derived from a higher intellect, through which it can illuminate phantasms. We know this from experience when we perceive ourselves abstracting universal forms from particular conditions—which is what it is to render things actually intelligible. But as was explained above (q. 76, a. 1) when we were discussing the passive intellect, an action belongs to a being only through some principle that formally inheres in it. Therefore, the power that is the principle of this action must be something within the soul. This is why Aristotle compared the active intellect to light, which is something received in the air.
Plato, on the other hand, compared the separated intellect that leaves an impression on our souls (imprimentem in animas nostras) to the sun, as Themistius reports in his commentary on De Anima 3. Now according to the teaching of our Faith, this separated intellect is God Himself, who is the creator of the soul and in whom alone the soul is beatified, as will become clear below (q. 90, a. 3 and ST 1-2, q. 3, a. 7). Hence, it is because of Him that the human soul participates in the intellectual light—this according to Psalm 4:7 (“The light of your countenance, O Lord, is signed upon us”).
Aquinas on creation and the related issue of the eternity of the world:
Aquinas on Creation in the Commentary on the Sentences:
[I]t should be known that the notion of creation involves two things. The first is that it presupposes nothing in the thing which is said to be created. Hence, in this it differs from all other changes, because generation presupposes matter which is not generated but through generation is made complete as transformed into the act of a form, while for the other <kinds of> changes a subject which is a complete being is presupposed. Hence, the causality of what generates or changes does not extend itself to everything found in the thing but [only] to the form which is educed from potency into act. But the causality of creating extends itself to all that is in the thing. For this reason creation is said to be from nothing because there is nothing which preexists creation as if uncreated. The second is that in the thing which is said to be created non being is prior to being, not by a priority of time or duration so that earlier it was not and afterwards it is, but by a priority of nature in such a way that if the created thing is left to itself non being would result. For it has being only from the influence of a superior cause. For what does not have being from another is prior to what has being from another. On the basis of this creation differs from eternal generation, for it cannot be said that, if left to himself the Son of God does not have being, since he receives from the Father that very same being which belongs to the Father, which is unqualified being not dependent on anything.
For those two reasons creation is said to be from nothing in two ways. One is such that the negation negates the order of creation in regard to something preexisting implied by the preposition from, so that being is said to be from nothing because it is not from something preexisting. That is with respect to the first. The other is such that the order of creation in regard to nothing preexisting remains affirmed with respect to nature so that creation is said to be from nothing because the thing created naturally has non being prior to being. If these two suffice for the notion (ratio) of creation, then creation can be demonstrated in this way and in this way the philosophers have asserted creation. However, if we take a third [consideration] to be required for the meaning of creation so that the thing created has non being in duration before being so that it is said to be from nothing because it is temporally after nothing, creation cannot be demonstrated in this way nor is this conceded by the philosophers, but is supposed by faith.
Aquinas on the eternity of the world
(http://dhspriory.org/thomas/DeEternitateMundi.htm)
It remains to be seen, then, whether there is a contradiction in saying that something made has always existed, on the grounds that it may be necessary that its non-being precede it in time, for we say that it is made out of nothing. But that there is no contradiction here is shown by Anselm in his explanation of what it means to say that a creature is made out of nothing. He says (Monologion cap. 8), "The third sense in which we can say that something is made out of nothing is this: we understand that something is made, but that there is not something from which it is made. In a similar way, we say that someone who is sad without reason is sad about nothing. We can thus say that all things, except the Supreme Being, are made by him out of nothing in the sense that they are not made out of anything, and no absurdity results." On this understanding of the phrase "out of nothing," therefore, no temporal priority of non-being to being is posited, as there would be if there were first nothing and then later something.
Further, let us even suppose that the preposition "out of" imports some affirmative order of non-being to being, as if the proposition that the creature is made out of nothing meant that the creature is made after nothing. Then this expression "after" certainly implies order, but order is of two kinds: order of time and order of nature. If, therefore, the proper and the particular does not follow from the common and the universal, it will not necessarily follow that, because the creature is made after nothing, non-being is temporally prior to the being of the creature. Rather, it suffices that non-being be prior to being by nature. Now, whatever naturally pertains to something in itself is prior to what that thing only receives from another. A creature does not have being, however, except from another, for, considered in itself, every creature is nothing, and thus, with respect to the creature, non-being is prior to being by nature. Nor does it follow from the creature's always having existed that its being and non-being are ever simultaneous, as if the creature always existed but at some time nothing existed, for the priority is not one of time. Rather, the argument merely requires that the nature of the creature is such that, if the creature were left to itself, it would be nothing. For example, if we should say that the air has always been illuminated by the sun, it would be right to say that the air has always been made lucid by the sun. Thus, since anything that comes to be such-and-such comes to be such-and-such from being not such-and-such, we say that the air is made lucid from being non-lucid, or opaque, not because the air was once non-lucid or opaque, but because the air would be opaque if the sun did not illuminate it. This is clearly the case with the stars and those celestial bodies that are always illuminated by the sun.
Thus it is clear that there is no contradiction in saying that something made by God has always existed. Indeed, if there were some contradiction, it would be amazing that Augustine failed to see it, for exposing such a contradiction would be a most effective way of proving that the world is not eternal, and although Augustine offers many arguments against the eternity of the world in XI and XII De Civitate Dei, he never argues that his opponents' view is contradictory. On the contrary, Augustine seems to hint that there is no contradiction involved. Thus, speaking of the Platonists, he says (X De Civitate Dei cap. 31), "They somehow contemplate a beginning in causation rather than a beginning in time. Imagine, they say, a foot that has been in dust since eternity: a footprint has always been beneath it, and nobody would doubt that the footprint was made by the pressure of the foot. Though neither is prior in time to the other, yet one is made by the other. Likewise, they say, the world and the gods in it have always existed, just as he who made them always existed; yet nevertheless, they were made." [PL 41, 311] Nor does Augustine ever say that this cannot be understood; rather, he proceeds against the Platonists in a totally different way. He says (XI De Civitate Dei cap. 4), "Those, however, who admit that the world was made by God but nevertheless want to hold that the world has a beginning in creation but not in time, so that, in some scarcely intelligible way, it has always been made by God, think that they are defending God against a charge of casual rashness." [PL 41, 319][8] Their position is difficult to understand, however, only for the reason given above in the first argument.
