102. Psychology. -- St. Augustine is a psychologist in the fullest sense of the word. His analysis of psychical states testifies to his extraordinary power of introspection.

(1) Nature of Man. -- The soul is spiritual. St. Augustine proves its spirituality from the peculiar abstract, universal, necessary character of our intellectual representations, and from the knowledge which the soul has of itself; its immortality he proves from its spirituality and from its possession of those same immutable and necessary truths. But about the problem of the soul's origin the African philosopher is evidently agitated by embarrassing doubts, -- which were transmitted from his time down to the earlier epochs of the Middle Ages. On the one hand, the doctrine of the propagation of original sin inclines him towards traducianism or generationism, in which the soul of the child is supposed to be sprung from the souls of its parents. On the other hand, he does not explicitly reject creationism, which teaches that human souls are created by God ex nihilo at the moment of their union with the body. Man has only one soul, single and simple (against Plato, 27), present throughout the whole body. United with the body it constitutes the human being.

The soul and the body preserve each its own substantiality. The soul makes use of the body ("homo anima rationalis est mortali atque terreno utens corpore," De moribus Eccl. Cath., I., xxvii.) and governs it ("regendo corpori accommodata," De Quant. Animae, xiii.). These statements clearly reveal their Platonic inspiration. St. Augustine never fully freed himself from Platonic influences, though here and there he makes use of formulas which are apparently inspired from other sources.

(2) The soul reveals itself in numerous activities which are not really distinct from its substance. Three faculties especially he recognizes, the memory, the understanding and the will, -- one of the numerous trichotomies in his psychology, and one in which he readily sees an image of the Holy Trinity. Let us consider a little more fully his teaching on intelligence and will.

(3) Intelligence. -- A certain dogmatic postulate lies at the basis of his theory of intellectual cognition. Against the scepticism of the Academy, which he had at one time professed, he lays down the thesis that certitude exists and is necessary for happiness. A primordial certitude is that of our own consciousness ("noli foras ire, in te redi, in interiori homine habitat veritas," De Vera Relig., 72) and of the reality of a thinking self ("omnis qui se dubitantem intelligit, verum intelligit, et de hac re quam intelligit certus est," ibid., 73). We are also certain of the first principles of the logical, metaphysical and ethical orders, and of our intellectual representations of the external world (ratio, intellectus). If we repose in these latter a confidence which we refuse to our sense-perceptions with their fugitive and ever-varying data (Plato), it is because we know the rule or standard of their truth. This norma is the resemblance of our ideas to the Divine ideas, and, consequently, to objective reality (100). Our intellects were made to know the truth, because they are finite participations of the infinite intelligence. So that St Augustine solves the criteriological problem by connecting it deductively with his theodicy.

The role of Divine illumination in intellectual knowledge deserves very special notice. St. Augustine is fond of calling God the sun of the soul, the light of the intellect, in which we see the immutable truth of things ("ea non posse intelligi nisi ab alio quasi suo sole illustrentur," Solil., I., i., c. 8; "in quadam luce sui generis omnia quae cognoscit intueatur," De Trinit., xii., i5). The De Magistro represents God as the secret tutor of the soul. In the De Trinitate (xii., c. 1-7) he distinguishes the ratio inferior (quae intendit temporalibus) from the ratio superior (quae intendit aeternis conspiciendis aut consulendis).

These expressions and others like them had an important influence -- historically -- in the Middle Ages: the difficulty of interpreting them explains why advocates of opposing systems quoted them in turn, each in support of himself. It is certain that St. Augustine did not use them in an ontologistic sense, -- as if our intellects directly contemplated immutable truths in the Divine essence. It is no less certain that in several passages the illuminative action of God has reference to the creative act, to which the soul and intellect owe their reality (e.g., De Civit. Dei, x., 2). But it is a far more delicate point to decide whether St. Augustine meant to solve the question of the origin of our ideas, or whether those formulas of his are only so many paraphrases of his favourite doctrine on the nature of intellectual knowledge and the ultimate foundation of its certitude. Is God the efficient cause of our ideas, impressing them on our intellects as the seal leaves its impress on the wax (De Trinit., xiv., 15), -- or does he simply mean that the necessity and immutability of those objective concepts and judgments spring from the fact that the essences of all things are necessarily and immutably conformable with their uncreated exemplar, the foundation of all truth (incommutabilia vera)?^{1} The latter explanation -- commonly accepted,^{2} and demanded by a certain number of passages, -- is more in keeping with the general spirit of the Augustinian theory of Ideas (100), which is manifestly borrowed from Plato. But this perhaps does not exclude the former interpretation, which is likewise supported by other passages, and harmonizes quite as well with the data of the Augustinian ideogeny, and with the saint's proofs of the existence of God.

What is the origin of our ideas? -- The Bishop of Hippo at first pronounced in favour of the Platonic theory of reminiscence (De Quantitate Animae, 20); and afterwards when he retracted this ideology, it was only because he rejected the Platonic theory of the pre-existence of souls. He substituted the view that the soul by virtue of its rational nature, can discover its knowledge by reflection on itself.^{3}

The function attributed by St. Augustine to the bodily senses in the production of sensation fits in with this innatist ideogeny. The psychic phenomenon is accomplished in the soul ("sensum puto esse non latere animam quod patitur corpus," De Quantitate Animae, c. 23, 41): the body does not act on the soul at all, for what is inferior cannot act on what is superior.^{4} It is not the body that by its causal action impresses its image on the soul, but the soul that engenders in itself an image of the body. Our ideas then are innate (Plato).^{5} And this being so, their actual presence in consciousness is explained by the repeated intervention of God, according as our intellects develop; as well as by one single act of His when, at the instant of its union with the body, He deposited in the soul a hidden treasure of knowledge.

(4.) The Will plays a preponderating role in our psychic life. -- St. Augustine declares himself for its primacy of honour over the intellect. Not only do the inner senses and the intellect act at its command, but purity of the will and its desires is a condition of knowledge. Only the soul that is pure and holy ("quae sancta et pura fuerit," Lib. 83 qq., 66) can aspire to a knowledge of truth by the ratio superior. Truth is a good that every one must love with all the energy of his soul (99). Further, the adherence of the mind to certain difficult truths -- like that of the union of soul and body -- is secured only by the intervention of the will. Lastly, the will enjoys this other prerogative: it is psychologically and morally free.

{1} See the exposition of this question by PORTALIÉ (op. cit., vol. i., col. 2234 and fol.), who gives to this theory of St. Augustine an exclusively ideogenic sense: God produces in us successively our different ideas.

{2} It is very well expounded and defended in KLEUTGEN, La Philosophie Scolastique (1869), vol. ii., pp. 411-51.

{3} "Illud quod dixi 'omnes sites animam secum attulisse mihi videtur . . .' non sic accipiendum est, quasi ex hoc approbetur, animam vel hic in alio corpore, vel alibi . . . aliquando vixisse: et ea quae interrogata respondet, cum hic non didicent, in alia vita ante didicisse" (L. xii., De Trinit., c. 15). "Fieri enim potest, sicut jam in hoc opere supra diximus (c. 4), ut hoc ideo possit, quia natura intelligibilis est, et connectitur non solum intelligibilibus, verum etiam immutabilibus rebus, eo ordine facta, ut cum se ad eas res movet quibus connexa est, vel ad seipsam, inquantum eas videt, intantum de his vera respondeat" (Retract., i., 8).

{4} Cf. OTT, Des hl. Augustinus Lehre über die Sinneserkenntniss (Philos. Jahrb., 1900, p. 50).

{5} "When he began to write, St. Augustine taught the doctrine of innate ideas, and he clung to it to the end". -- J. MARTIN, S. Augustin, p. 51.