At the time of your defeat, when you are bound both with languor and slothfulness, and subdued by the enemy in the most painful misery and wearisome labor of sin, ponder in your heart on the former time of your diligence, and how you used to concern yourself even over the most minute matters, and the valiant struggle which you displayed, and how you were stirred up with zeal against those who would hinder you in your progress. Furthermore, reflect upon the groans which you used to utter because of the small faults that you committed due to your negligence, and how in all these things you took the crown of victory. For thus, with such and so many recollections, your soul is wakened as if from the deep and is clad with the flame of zeal.

The Ascetical Homilies of Isaac the Syrian