Chapter IV -- 9
St Thomas establishes that the ‘memory’ is part of the intellect. It should be recalled that this ‘memory’ is not the memorative power that is a part of the sensitive soul, what we would understand today by ‘memory’. This memory is the power of the intellect to preserve intelligible species—let us say here, the subjective representations of concepts.
St Thomas asserts that the memory is none other than the intellect itself.
St Thomas asserts that the reason and the intellect are the same thing. This is very important, for by ‘reason’ St Thomas always means the power of ratiocination: the power of reasoning by syllogisms or even by the rules of some other system of logic. This is intimately connected to St Thomas’ doctrine that man in the present life can only know intelligible realities by means of ratiocination working with propositions based on concepts abstracted from sense-perceptions, although after death he will have an angel-like intuitive mode of apprehension of those intelligible realities. We will see below that in making this assertion St Thomas is most likely addressing the intuitive, Augustinian notion of ‘intellect’.
St Thomas asserts that the ‘superior reason’ and the ‘inferior reason’ are the same power. He takes the concepts of the superior and inferior reason from
This is very important to understand. St Thomas is making a very important and basic move in his psychology: he is asserting that any power that a man might have in this life to apprehend intelligible realities intuitively, and indeed any intellectual power that a man might have at all, is completely assimilated to man’s reason, which is to be identified strictly with man’s power of ratiocination.
We find this topic developed in some detail in a passage taken from another work of St Thomas. This development is very difficult to understand without a complete grounding in St Thomas’ philosophy, but the basic sense is this: Man’s reason has a capacity to apprehend intuitively the first principles of reason such as the law of the excluded middle, the notion that the whole is greater than the part and the law of cause and effect. This intuitive power to grasp the first principles of reason is the most intuitive power that a man’s intellect has, one which, in the great hierarchy of intellects that we have just discussed, brings man to the border of the angelic world, since angels apprehend intelligible realities exclusively in an intuitive way. This intuitive apprehension by man’s intellect of certain basic epistemological principles is the full extent of man’s capacity in this life intuitively to apprehend intelligible realities. For the rest, man must reason by syllogisms using concepts that he abstracts from the sense-perceptions of material objects.
St Thomas then identifies the ‘intelligence’ with the intellect. ‘Intelligence’ is a concept that St Thomas takes from St Augustine, although it is not clear just what St Thomas means by ‘intelligence’ as distinct from the ‘intellect’, even though angels are ‘intelligences’. It is certain, however, that St Thomas is systematically establishing that all the functions or powers of the intellect or mind are in fact one: reason.
St Thomas next establishes that the speculative reason (that which attains to general truths) and the practical reason (that which attains to practical results and works) are the same power.
Many of the terms that St Thomas has reduced to the reason in the preceding articles are taken from St Augustine, especially ‘intellect’, the ‘superior reason’, the ‘inferior reason’, ‘intelligence’, and possibly also ‘memory’. What St Thomas is doing is dismissing Augustinian psychology: to say that he is reinterpreting it would be to suggest that he is retaining some part of it, which he is not. Augustinian psychology is quite interesting in its own right, but it would be burdensome to the reader for us to spend much time on it.
However, since it has certain points of contact with the psychology that underlies the Philokalia, it is worthwhile to delineate its outlines: The mind (mens) is the superior part of the reasonable soul; it adheres to intelligibles and to God. It contains the reason (ratio) and the intelligence (intelligentia). Reason (ratio) is the movement of the mind (mens). The most eminent part of the mens is the intelligence (intelligentia). ‘Intelligence (intelligentia)’ can be considered synonymous with ‘intellect (intellectus)’.
The intellect (intellectus) is a faculty of the soul, proper to man, which is directly illuminated by the divine light: ‘Thus in our soul is a certain thing which is called intellect (intellectus). This very thing which is called intellect (intellectus) and mind (mens) is illuminated by the superior light. Now that superior light by which the human mind (mens) is illuminated is God.’ The intellect (intellectus) is a faculty superior to the reason, because one can have reason without having intelligence (intelligentia) or intellect (intellectus), but one cannot have intelligence without first having reason, and that is so because one attains to intelligence by means of the reason. In a word, the intelligence is an interior sight, by which the mind perceives the truth which the divine light uncovers to it.
Note that the final sentence indicates that the ‘intelligence (intelligentia)’ is a faculty of intuitive apprehension.
It can be seen that the import of St Thomas’ reduction of these Augustinian terms to the reason, taken always as ratiocination, is to sweep away St Augustine’s psychology. We will discuss other aspects of St Augustine’s psychology as we proceed.
It should be noted that Fr Copleston has a somewhat broader concept of the Thomist reason than we have delineated.
 ST Ia, 79, 3.
 ST Ia, 79, 6.
 We think that St Thomas might also have in mind here the memory that St Augustine discusses; we will see below why this might be so.
 ST Ia, 79, 7.
 ST Ia, 79, 8.
 ST Ia, 79, 9.
 See Gilson E pp. 240–1.
 ST Ia, 79, 10.
 ST Ia, 79, 11.
 In Joan. Evang. tract XV, 4, 19; our translation from the Latin.
 Sermo 43, II, 3–III, 4.
 Enarr. in Ps. 32, 22.
 We are in this paragraph paraphrasing Gilson Aug p. 56, fn. 1, d.
 Copleston Volume II, p. 378.