How we should struggle against appearances Every habit and faculty is maintained and increased by the corresponding actions: the habit of walking by walking, the habit of running by running. If you would be a good reader, read; if a writer, write. But when you shall not have read thirty days in succession, but have done something else, you will know the consequence. In the same way, if you shall have lain down ten days, get up and attempt to make a long walk, and you will see how your legs are weakened. Generally, then, if you would make anything a habit, do it; if you would not make it a habit, do not do it, but accustom yourself to do something else in place of it.

So it is with respect to the affections of the soul: when you have been angry, you must know that not only has this evil befallen you, but that you have also increased the habit, and in a manner thrown fuel upon fire.

When you have been overcome in sexual intercourse with a person, do not reckon this single defeat only, but reckon that you have also nurtured, increased your incontinence. For it is impossible for habits and faculties, some of them not to be produced, when they did not exist before, and others not be increased and strengthened by corresponding acts.