11. There is no Saint however holy and innocent who may not truly consider himself the greatest sinner in the world. It is enough that he knows himself to be man to recognize that he is liable to commit all the evil of which man is capable. As man, I have in my corrupt nature a proclivity to every evil; and so far as I am concerned I am quite capable of committing all kinds of sin, and if I do not commit them it is through a special grace of God which preserves and restrains me.

A tree does not fall while bending under its own weight, and this must be attributed to the strength of its support; and in the same way if I have not fallen into every kind of iniquity, it must not be attributed to my own inherent virtue but only to Divine grace, which by its goodness has supported me. Therefore how can I esteem myself more than another whilst we are all equal in human weakness? "For what is my strength?" [Job vi, 11] I am a son of Adam like every other man, born in sin, inclined to sin, and ever ready to fall into sin. I have no need of the devil to tempt me to sin; my own concupiscence is only too great a temptation; and if God were to withdraw from me His protecting and helping hand, I know that I should be precipitated headlong from bad to worse. 

When St. Augustine made his examen of conscience, he did not always find sufficient to excite within him sorrow and contrition, so he dwelt on those sins which he might or would have committed had he not been preserved from them by God's infinite mercy; and he grieved and accused himself and humbly implored pardon of God for the evil capacity he had to commit all kinds of heinous and impious sins. In this practice is to be found an exercise of true humility.