Et hoc oro, ut caritas vestra magis ac magis abundet in scientia et in omni sensu.
And this I pray: That your charity may more and more abound in knowledge and in all sense.
(Philippians 1:9)
caritas est Spiritus, de quo dicitur Io. XVI, 13: cum venerit ille Spiritus veritatis, docebit vos omnem, et cetera. Cuius ratio est, quia qui habet habitum, si rectus est habitus, sequitur inde rectum iudicium de his quae pertinent ad illum habitum; si vero corruptus, falsum. Sicut circa venerea temperatus habet bonum iudicium, intemperatus non sed falsum.
Omnia autem quae a nobis fiunt, sunt informanda caritate, et ideo habens caritatem, habet rectum iudicium, et quantum ad cognoscibilia. Et sic dicit in omni scientia, qua scilicet agnoscat veritatem et inhaereat circa ea quae sunt fidei. Haec est scientia sanctorum, de qua dicitur Sap. X, 10.
The Spirit is Charity, of which it is said in John 16:13 ‘when the Spirit of truth comes, he will guide you into all the truth.’ The reason for this is that whoever has a habit, if the habit is right, there follows thence right judgement about those things which pertain to that habit; but if corrupt, false judgement. Just as, concerning venereal pleasures, the temperate man has good judgment, while the intemperate does not but has false judgement.
But everything which comes from us should be informed by charity, and therefore he who has charity has right judgement also about knowable things. And thus he says ‘in all knowledge,’ namely that with which one recognises truth and adheres to those things which are of faith. This is the science of the saints about which is spoken of in Wisdom 10:10.
(St. Thomas, Commentary on Philippians C.1 L.2 n.17)