Entry 0392: Commentary on
De veritate, question 10, article 8, ad 13
Aquinas uses the expression actus essendi in one more text in De veritate, in question 10, article 8, ad 13.
The question asked in this article is whether the human soul knows itself per essentiam or per speciem. The question is whether the essence of the human soul is itself that whereby the human soul knows itself: Et hoc modo ad praesens quaeritur utrum anima per suam essentiam intelligat se.
One of the difficulties Aquinas faces in this question is that in order to say that the human soul knows itself per essentiam, the object known and that whereby the object is made known have to be identical. If this is not the case, then that whereby the human soul is made known would have to be something other than the human soul itself, and therefore the human soul would not be knowing itself per essentiam.
Here Aquinas reasons that the form and that which the form informs cannot be the same under the same aspect. The intellectual faculty, for example, informs the human soul as property to subject. Thus, the potentia intellectiva is an accidental form that inheres in the human soul. But the human soul cannot in this way be the form of the intellectual faculty. The relationship between the human soul and the intellective power can then be considered in two ways: (1) in regard to the order of the real, that is to say, quantum ad actum essendi; and (2) in regard to the conceptual order, that is to say, quantum ad actum intelligendi.
With reference to the actus essendi, the essence of the human soul cannot be said to be an intelligible form that informs the possible intellect directly. But in the order of understanding, the human soul can be made the object of knowledge.
Aquinas distinguishes four ways in which the human soul can be made the object of knowledge: the first is knowledge of the human soul in answer to the question an est in the habitual mode; the second is knowledge of the human soul in answer to the question an est in the actual mode; the third is knowledge of the quiddity of the human soul by way of apprehension; and the fourth is knowledge of the quiddity of the human soul by way of judgment. The last three ways of knowing the human soul are accomplished per speciem.
Only in the first way of knowing, that of answering to the question an est in the habitual mode, can the human soul be said to directly know itself through its essence. Aquinas illustrates this with the example of one’s own awareness of being alive: “No one has ever made the mistake of not perceiving that he was alive, a fact which belongs to the knowledge by which one knows in its singularity what goes on in his soul. It is according to this knowledge that the soul is said to be habitually known through its essence” (De veritate, question 10, article 8, ad 2, Rome: Leonine edition, 1970, vol. 22, fasc. 2/1, p. 323 column A, lines 335-341: “Ad secundum dicendum quod nullus unquam erravit in hoc quod non perciperet se vivere, quod pertinet ad cognitionem qua aliquis singulariter cognoscit quid in anima sua agatur; secundum quam cognitionem dictum est quod anima per essentiam suam cognoscitur in habitu.”).
The conclusion of the analysis is that although the human soul can in some fashion directly know itself through its essence, ordinarily the human soul knows itself per speciem.
Regarding the use of the expression actus essendi in this article, here is Aquinas in his own words:
Praeterea, non potest idem (esse) forma et formatum respectu eiusdem; sed intellectus, cum sit quaedam potentia animae, est quasi quaedam forma essentiae ipsius; ergo non potest esse quod essentia animae sit forma intellectus, sed id quo aliquid intelligitur est forma intellectus; ergo mens non videt se ipsam per essentiam suam. (Rome: Leonine edition, 1970, vol. 22, fasc. 2/1, p. 319 Column B, line 87 - p. 320 column A, line 94).
Ad tertium decimum dicendum quod intellectiva potentia est forma ipsius animae quantum ad actum essendi eo quod habet esse in anima sicut proprietas in subiecto; sed quantum ad actum intelligendi nihil prohibet esse e converso. (Rome: Leonine edition, 1970, vol. 22, fasc. 2/1, p. 324 column A, lines 412-417).
Of the thirteen texts in which Aquinas explicitly uses the expression actus essendi, the present text (De Veritate, question 10, article 8, ad 13) is the only one in which the expression actus essendi seems at first to refer to something other than a subsisting thing. From the context, however, there is no question that Aquinas is not introducing a modification of his understanding of the doctrine of the real distinction between actus essendi and quod est. The part of the statement that contains the expression actus essendi should be read as saying “quantum ad actum essendi [animae.]”
The res significata of the expression actus essendi is clarified by indicating that the esse of the potentia intellectiva is the esse of a proprietas in subiecto. Aquinas teaches that in the real world, only a subsisting subject possesses esse in the sense of actus essendi. Accordingly, in the answer to the previous objection (in De Veritate, question 10, article 8, ad 12) Aquinas remarks that the quo est that belongs to the human soul is what he calls actus entis. For Aquinas, the human soul is indeed a subsisting subject in which a real distinction and a real composition of quo est (understood as actus essendi) and quod est (understood as the subsisting subject which possesses the actus essendi) is found.
Here is Aquinas in his own words:
Praeterea, posteriora sunt magis composita prioribus; sed intelligere est posterius quam esse; ergo in intelligentia animae invenitur maior compositio quam in eius esse; sed in anima non est idem quod est et quo est; ergo nec in ea est idem quod intelligitur et quo intelligitur, et sic mens non se videt per suam essentiam. (Rome: Leonine edition, 1970, vol. 22, fasc. 2/1, p. 319 column B, lines 79-86).
Ad duodecimum dicendum quod quo intelligitur et quod intelligitur, non hoc modo se habent ad invicem sicut quo est et quod est: esse enim est actus entis, sed intelligere non est actus eius quod intelligitur sed intelligentis; unde quo intelligitur comparatur ad intelligentem sicut quo est ad quod est. Et ideo sicut in anima est aliud quo est et quod est, ita aliud est quo intelligit, idest potentia intellectiva, quae est principium actus intelligendi, a sua essentia. Non autem ex hoc oportet quod species qua intelligitur sit aliud ab eo quod intelligitur. (Rome: Leonine edition, 1970, vol. 22, fasc. 2/1, p. 323 Column B, line 400 - p. 324 column A, line 411).