Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that understanding is not a part of prudence. When two things are members of a division, one is not part of the other. But intellectual virtue is divided into understanding and prudence, according to Ethic. vi, 3. Therefore understanding should not be reckoned a part of prudence.

Objection 2: Further, understanding is numbered among the gifts of the Holy Ghost, and corresponds to faith, as stated above (Question 8, Articles 1,8). But prudence is a virtue other than faith, as is clear from what has been said above (Question 4, Article 8; 1.2, Question 62, Article 2). Therefore understanding does not pertain to prudence.

Objection 3: Further, prudence is about singular matters of action (Ethic. vi, 7): whereas understanding takes cognizance of universal and immaterial objects (De Anima iii, 4). Therefore understanding is not a part of prudence.

On the contrary, Tully accounts "intelligence" a part of prudence, and Macrobius mentions "understanding," which comes to the same.

I answer that, Understanding denotes here, not the intellectual power, but the right estimate about some final principle, which is taken as self-evident: thus we are said to understand the first principles of demonstrations. Now every deduction of reason proceeds from certain statements which are taken as primary: wherefore every process of reasoning must needs proceed from some understanding. Therefore since prudence is right reason applied to action, the whole process of prudence must needs have its source in understanding. Hence it is that understanding is reckoned a part of prudence.

Reply to Objection 1: The reasoning of prudence terminates, as in a conclusion, in the particular matter of action, to which, as stated above (Question 47, Articles 3,6), it applies the knowledge of some universal principle. Now a singular conclusion is argued from a universal and a singular proposition. Wherefore the reasoning of prudence must proceed from a twofold understanding. The one is cognizant of universals, and this belongs to the understanding which is an intellectual virtue, whereby we know naturally not only speculative principles, but also practical universal principles, such as "One should do evil to no man," as shown above (Question 47, Article 6). The other understanding, as stated in Ethic. vi, 11, is cognizant of an extreme, i.e. of some primary singular and contingent practical matter, viz. the minor premiss, which must needs be singular in the syllogism of prudence, as stated above (Question 47, Articles 3,6). Now this primary singular is some singular end, as stated in the same place. Wherefore the understanding which is a part of prudence is a right estimate of some particular end.

Reply to Objection 2: The understanding which is a gift of the Holy Ghost, is a quick insight into divine things, as shown above (Question 8, Articles 1,2). It is in another sense that it is accounted a part of prudence, as stated above.

Reply to Objection 3: The right estimate about a particular end is called both "understanding," in so far as its object is a principle, and "sense," in so far as its object is a particular. This is what the Philosopher means when he says (Ethic. v, 11): "Of such things we need to have the sense, and this is understanding." But this is to be understood as referring, not to the particular sense whereby we know proper sensibles, but to the interior sense, whereby we judge of a particular.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod intellectus non sit pars prudentiae. Eorum enim quae ex opposito dividuntur unum non est pars alterius. Sed intellectus ponitur virtus intellectualis condivisa prudentiae, ut patet in VI ethic..

Ergo intellectus non debet poni pars prudentiae.

Argumentum 2

Praeterea, intellectus ponitur inter dona spiritus sancti, et correspondet fidei, ut supra habitum est.

Sed prudentia est alia virtus a fide, ut per supradicta patet.

Ergo intellectus non pertinet ad prudentiam.

Argumentum 3

Praeterea, prudentia est singularium operabilium, ut dicitur in VI ethic..

Sed intellectus est universalium cognoscitivus et immaterialium; ut patet in III de anima.

Ergo intellectus non est pars prudentiae.

Sed Contra

Sed contra est quod tullius ponit intelligentiam partem prudentiae, et Macrobius intellectum, quod in idem redit.

Corpus

Respondeo dicendum quod intellectus non sumitur hic pro potentia intellectiva, sed prout importat quandam rectam aestimationem alicuius extremi principii quod accipitur ut per se notum, sicut et prima demonstrationum principia intelligere dicimur. Omnis autem deductio rationis ab aliquibus procedit quae accipiuntur ut prima. Unde oportet quod omnis processus rationis ab aliquo intellectu procedat. Quia igitur prudentia est recta ratio agibilium, ideo necesse est quod totus processus prudentiae ab intellectu derivetur.

Et propter hoc intellectus ponitur pars prudentiae.

Ad 1

Ad primum ergo dicendum quod ratio prudentiae terminatur, sicut ad conclusionem quandam, ad particulare operabile, ad quod applicat universalem cognitionem, ut ex dictis patet.

Conclusio autem singularis syllogizatur ex universali et singulari propositione. Unde oportet quod ratio prudentiae ex duplici intellectu procedat. Quorum unus est qui est cognoscitivus universalium. Quod pertinet ad intellectum qui ponitur virtus intellectualis, quia naturaliter nobis cognita sunt non solum universalia principia speculativa, sed etiam practica, sicut nulli esse malefaciendum, ut ex dictis patet.

Alius autem intellectus est qui, ut dicitur in VI ethic., est cognoscitivus extremi, idest alicuius primi singularis et contingentis operabilis, propositionis scilicet minoris, quam oportet esse singularem in syllogismo prudentiae, ut dictum est.

Hoc autem primum singulare est aliquis singularis finis, ut ibidem dicitur.

Unde intellectus qui ponitur pars prudentiae est quaedam recta aestimatio de aliquo particulari fine.

Ad 2

Ad secundum dicendum quod intellectus qui ponitur donum spiritus sancti est quaedam acuta perspectio divinorum, ut ex supradictis patet.

Aliter autem ponitur intellectus pars prudentiae, ut dictum est.

Ad 3

Ad tertium dicendum quod ipsa recta aestimatio de fine particulari et intellectus dicitur, inquantum est alicuius principii; et sensus, inquantum est particularis.

Et hoc est quod philosophus dicit, in VI ethic., horum, scilicet singularium, oportet habere sensum, hic autem est intellectus.

Non autem hoc est intelligendum de sensu particulari quo cognoscimus propria sensibilia, sed de sensu interiori quo de particulari iudicamus.