declares (Ethic. x, 4); and the same can apply to the generation of animals.  Accordingly sins are divided into these three, viz. sins of thought, word, and deed, not as into various complete species:  for the consummation of sin is in the deed, wherefore sins of deed have the complete species; but the first beginning of sin is its foundation, as it were, in the sin of thought; the second degree is the sin of word, in so far as man is ready to break out into a declaration of his thought; while the third degree consists in the consummation of the deed.  Consequently these three differ in respect of the various degrees of sin.  Nevertheless it is evident that these three belong to the one complete species of sin, since they proceed from the same motive.  For the angry man, through desire of vengeance, is at first disturbed in thought, then he breaks out into words of abuse, and lastly he goes on to wrongful deeds; and the same applies to lust and to any other sin.

Reply Obj. 1:  All sins of thought have the common note of secrecy, in respect of which they form one degree, which is, however, divided into three stages, viz. of cogitation, pleasure, and consent.

Reply Obj. 2:  Sins of words and deed are both done openly, and for this reason Gregory (Moral. iv, 25) reckons them under one head:  whereas Jerome (in commenting on Ezech. 43:23) distinguishes between them, because in sins of word there is nothing but manifestation which is intended principally; while in sins of deed, it is the consummation of the inward thought which is principally intended, and the outward manifestation is by way of sequel.  Habit and despair are stages following the complete species of sin, even as boyhood and youth follow the complete generation of a man.

Reply Obj. 3:  Sin of thought and sin of word are not distinct from the sin of deed when they are united together with it, but when each is found by itself:  even as one part of a movement is not distinct from the whole movement, when the movement is continuous, but only when there is a break in the movement. ________________________

EIGHTH ARTICLE [I-II, Q. 72, Art. 8]

Whether Excess and Deficiency Diversify the Species of Sins?

Objection 1:  It would seem that excess and deficiency do not diversify the species of sins.  For excess and deficiency differ in respect of more and less.  Now “more” and “less” do not diversify a species.  Therefore excess and deficiency do not diversify the species of sins.

Obj. 2:  Further, just as sin, in matters of action, is due to straying from the rectitude of reason, so falsehood, in speculative matters, is due to straying from the truth of the reality.  Now the species of falsehood is not diversified by saying more or less than the reality.  Therefore neither is the species of sin diversified by straying more or less from the rectitude of reason.

Obj. 3:  Further, “one species cannot be made out of two,” as Porphyry declares [Isagog.; cf.  Arist. _Metaph._ i].  Now excess and deficiency are united in one sin; for some are at once illiberal and wasteful—­illiberality being a sin of deficiency, and prodigality, by excess.  Therefore excess and deficiency do not diversify the species of sins.