Padre Quadrupani draws a thick line between involuntarily temptations and the voluntary commission of sin.
“The attraction of the feelings towards the object presented by the imagination is at times so strong that the will seems to have been carried away and overcome by a sort of fascination. This, however, is not the case. The will suffered, but did not consent; it was attacked and wounded, but not conquered. This state of things coincides with what St. Paul says of the revolt of the flesh against the spirit and of their unceasing warfare. The soul, indeed, experiences strange sensations, but as she does not consent to them, she passes through the ordeal unsullied, just as substances coated with oil may be immersed in water without absorbing a single drop of it.”
“Should it frequently happen that you have not a distinct consciousness of your success against temptation, it may be that God refuses you this satisfaction in order that, lacking this clear assurance, your knowledge may come through obedience. . . . These doubts are but fresh artifices of the devil to rob you of the merit of obedience.”
“To constitute a mortal sin three conditions must co-exist. First, the matter must be weighty; secondly, the mind must have full knowledge of the guilt of the action, omission or dangerous occasion in question; and, thirdly, the will, through a criminal preference for the forbidden action, culpable omission, or proximate occasion of sin, must give full consent. These reflections should serve to reassure your mind if the fear of having committed a mortal sin disturb it, for it is very difficult for this threefold union of conditions to be effected in a God-fearing soul. However, perfect security can come, and ought to come, only from spiritual obedience.”
Quotations from Carlo Giuseppe Quadrupani, Light and Peace: Instructions for Devout Souls to Dispel Their Doubts and Allay Their Fears (St. Louis: B. Herder, 1898).