Reply Obj. 1: According to the Philosopher (Ethic. vi, 5), intemperance is the chief corruptive of prudence: wherefore the vices opposed to prudence arise chiefly from lust, which is the principal species of intemperance.
Reply Obj. 2: The constancy which is a part of fortitude regards hardships and objects of fear; but constancy in refraining from pleasures pertains to continence which is a part of temperance, as stated above (Q. 143). Hence the inconstancy which is opposed thereto is to be reckoned a daughter of lust. Nevertheless even the first named inconstancy arises from lust, inasmuch as the latter enfeebles a man's heart and renders it effeminate, according to Osee 4:11, "Fornication and wine and drunkenness take away the heart [Douay: 'understanding']." Vegetius, too, says (De Re Milit. iii) that "the less a man knows of the pleasures of life, the less he fears death." Nor is there any need, as we have repeatedly stated, for the daughters of a capital vice to agree with it in matter (cf. Q. 35, A. 4, ad 2; Q. 118, A. 8, ad 1; Q. 148, A. 6).
Reply Obj. 3: Self-love in respect of any goods that a man desires for himself is the common origin of all sins; but in the special point of desiring carnal pleasures for oneself, it is reckoned a daughter of lust.
Reply Obj. 4: The sins mentioned by Isidore are inordinate external acts, pertaining in the main to speech; wherein there is a fourfold inordinateness. First, on account of the matter, and to this we refer "obscene words": for since "out of the abundance of the heart the mouth speaketh" (Matt. 12:34), the lustful man, whose heart is full of lewd concupiscences, readily breaks out into lewd words. Secondly, on account of the cause: for, since lust causes thoughtlessness and rashness, the result is that it makes a man speak without weighing or giving a thought to his words, which are described as "scurrilous." Thirdly, on account of the end: for since the lustful man seeks pleasure, he directs his speech thereto, and so gives utterance to "wanton words." Fourthly, on account of the sentiments expressed by his words, for through causing blindness of mind, lust perverts a man's sentiments, and so he gives way "to foolish talking," for instance, by expressing a preference for the pleasures he desires to anything else. _______________________
QUESTION 154
OF THE PARTS OF LUST
(In Twelve Articles)
We must now consider the parts of lust, under which head there are twelve points of inquiry:
(1) Into what parts is lust divided?
(2) Whether simple fornication is a mortal sin?
(3) Whether it is the greatest of sins?