Usus rationis requirit debitum usum imaginationis et aliarum virium sensitivarum, quae utuntur organo corporali; et ideo ex transmutatione corporali usus rationis impeditur, impedito actu virtutis imaginativae et aliarum sensitivarum.
The use of reason requires the due use of the imagination and of the other sensitive powers, which are exercised through a bodily organ; consequently alteration in the body hinders the use of reason, because it hinders the act of the imagination and of the other sensitive powers.
Philosophus dicit, in VI Ethic., quod "delectatio corrumpit existimationem prudentiae".
The Philosopher says (Ethic. vi, 5), that "pleasure destroys the estimate of prudence".
Est ergo quaedam delectatio quae habetur de ipso actu rationis, sicut cum aliquis delectatur in contemplando vel ratiocinando. Et talis delectatio non impedit usum rationis, sed ipsum adiuvat, quia illud attentius operamur in quo delectamur, attentio autem adiuvat operationem.
There is a certain pleasure that is taken in the very act of reason, as when one takes pleasure in contemplating or in reasoning. And such pleasure does not hinder the act of reason, but helps it, because we are more attentive in doing that which gives us pleasure, and attention fosters activity.