Thomas Aquinas

“ It does not depend on the disposition of our appetite whether we judge well or ill of the principles of art, as it does, when we judge of the end which is the principle in moral matters: in the former case our judgment depends on reason alone. Hence art does not require a virtue perfecting the appetite, as prudence does. ”

“ Right reason which is in accord with prudence is included in the definition of moral virtue, not as part of its essence, but as something belonging by way of participation to all the moral virtues, in so far as they are all under the direction of prudence. ”

“ But this is not enough in order that man may reason aright about particular cases. For it happens sometimes that the aforesaid universal principle, known by means of understanding or science, is destroyed in a particular case by a passion: thus to one who is swayed by concupiscence, when he is overcome thereby, the object of his desire seems good, although it is opposed to the universal judgment of his reason. ”

“ Art. 5 - Whether there can be intellectual without moral virtue? Objection 1: It would seem that there can be intellectual without moral virtue. Because perfection of what precedes does not depend on the perfection of what follows. ”

“ And in this way, there is some truth in the saying of Socrates that so long as a man is in possession of knowledge he does not sin: provided, however, that this knowledge is made to include the use of reason in this individual act of choice. ”

“ I answer that, In order to answer this question clearly, we must consider the meaning of the Latin word "mos"; for thus we shall be able to discover what a "moral" virtue is. Now "mos" has a twofold meaning. ”

“ Prudence not only helps us to be of good counsel, but also to judge and command well. This is not possible unless the impediment of the passions, destroying the judgment and command of prudence, be removed ”

“ Because the appetitive faculty obeys the reason, not blindly, but with a certain power of opposition; wherefore the Philosopher says (Polit. i, 3) that "reason commands the appetitive faculty by a politic power," whereby a man rules over subjects that are free, having a certain right of opposition. Hence Augustine says on Ps. 118 (Serm. 8) that "sometimes we understand [what is right] while desire is slow, or follows not at all," in so far as the habits or passions of the appetitive faculty cause the use of reason to be impeded in some particular action. ”

“ This is clear from the fact that passions abound in the continent and persevering man, which would not be the case if his sensitive appetite were perfected by a habit making it conformable to reason. Contingency and perseverance are, however, perfections of the rational faculty, and withstand the passions lest reason be led astray. But they fall short of being virtues: since intellectual virtue, which makes reason to hold itself well in respect of moral matters, presupposes a right appetite of the end, so that it may hold itself aright in respect of principles, i.e. ”

“ Nor again can an action proceeding from two principles be perfect, unless each principle be perfected by the habit corresponding to that operation: thus, however perfect be the principal agent employing an instrument, it will produce an imperfect effect, if the instrument be not well disposed also. ”