Thomas Aquinas

“ Virtue and sin do not arise from the same source. For sin arises from the desire of mutable good; and consequently the desire of that good which helps one to obtain all temporal goods, is called the root of all sins. But virtue arises from the desire for the immutable God; and consequently charity, which is the love of God, is called the root of the virtues, according to Eph. ”

“ So when we say that covetousness is the root of all evils, we do not assert that no other evil can be its root, but that other evils more frequently arise therefrom, for the reason given.
Art. 2 - Whether pride is the beginning of every sin? Objection 1: It would seem that pride is not the beginning of every sin. For the root is a beginning of a tree, so that the beginning of a sin seems to be the same as the root of sin. ”

“ Or again, good moves the appetite chiefly through possessing some property of happiness, which all men seek naturally. Now in the first place happiness implies perfection, since happiness is a perfect good, to which belongs excellence or renown, which is desired by "pride" or "vainglory." Secondly, it implies satiety, which "covetousness" seeks in riches that give promise thereof. ”

“ Wherefore, in the passage quoted, apostasy from God does not denote the special sin, but rather that general condition of every sin, consisting in its turning away from God. It may also be said that apostasy from God is said to be the beginning of pride, because it is the first species of pride. For it is characteristic of pride to be unwilling to be subject to any superior, and especially to God; the result being that a man is unduly lifted up, in respect of the other species of pride. ”

“ Just as in natural things we do not ask what always happens, but what happens most frequently, for the reason that the nature of corruptible things can be hindered, so as not always to act in the same way ”

“ First, on account of the condition of the sinner, who is disposed so as to have a strong inclination for one particular end, the result being that he frequently goes forward to other sins. But this kind of origin does not come under the consideration of art, because man's particular dispositions are infinite in number. ”