At first a simple thought about evil makes it into the mind, a | DRIIIVΞR

At first a simple thought about evil makes it into the mind, and if it is kept in the mind, then a passionate motion arises from it, and if you do not extirpate the passion, then it inclines the mind to agreement, and when this happens, it leads the mind to the commission of a sinful deed. [Guard your thoughts], for if you do not sin in thought, you will never sin in deed.

St. Maximos the Confessor, Chapters on Love, 1.84, 2.78