The other causes of sin are extrinsic and remote, as it were, being those whereby the will is inclined to sin.  Among these causes we must make a distinction; for some of them induce the will to sin in accord with the very nature of the will:  such is the end, which is the proper object of the will; and by a such like cause sin is made more grievous, because a man sins more grievously if his will is induced to sin by the intention of a more evil end.  Other causes incline the will to sin, against the nature and order of the will, whose natural inclination is to be moved freely of itself in accord with the judgment of reason.  Wherefore those causes which weaken the judgment of reason (e.g. ignorance), or which weaken the free movement of the will, (e.g. weakness, violence, fear, or the like), diminish the gravity of sin, even as they diminish its voluntariness; and so much so, that if the act be altogether involuntary, it is no longer sinful.

Reply Obj. 1:  This argument considers the extrinsic moving cause, which diminishes voluntariness.  The increase of such a cause diminishes the sin, as stated.

Reply Obj. 2:  If concupiscence be understood to include the movement of the will, then, where there is greater concupiscence, there is a greater sin.  But if by concupiscence we understand a passion, which is a movement of the concupiscible power, then a greater concupiscence, forestalling the judgment of reason and the movement of the will, diminishes the sin, because the man who sins, being stimulated by a greater concupiscence, falls through a more grievous temptation, wherefore he is less to be blamed.  On the other hand, if concupiscence be taken in this sense follows the judgment of reason, and the movement of the will, then the greater concupiscence, the graver the sin:  because sometimes the movement of concupiscence is redoubled by the will tending unrestrainedly to its object.

Reply Obj. 3:  This argument considers the cause which renders the act involuntary, and such a cause diminishes the gravity of sin, as stated. ________________________

SEVENTH ARTICLE [I-II, Q. 73, Art. 7]

Whether a Circumstance Aggravates a Sin?

Objection 1:  It would seem that a circumstance does not aggravate a sin.  Because sin takes its gravity from its species.  Now a circumstance does not specify a sin, for it is an accident thereof.  Therefore the gravity of a sin is not taken from a circumstance.

Obj. 2:  Further, a circumstance is either evil or not:  if it is evil, it causes, of itself, a species of evil; and if it is not evil, it cannot make a thing worse.  Therefore a circumstance nowise aggravates a sin.

Obj. 3:  Further, the malice of a sin is derived from its turning away (from God).  But circumstances affect sin on the part of the object to which it turns.  Therefore they do not add to the sin’s malice.

On the contrary, Ignorance of a circumstance diminishes sin:  for he who sins through ignorance of a circumstance, deserves to be forgiven (Ethic. iii, 1).  Now this would not be the case unless a circumstance aggravated a sin.  Therefore a circumstance makes a sin more grievous.