It is the character of the incontinent man to pursue, without being convinced of their goodness, bodily pleasures that exceed the bounds of moderation and are contrary to right reason; but the profligate man is convinced that these things are good because it is his character to pursue them: the former, then, may be easily brought to a better mind, the latter not. For virtue preserves, but vice destroys the principle; but in matters of conduct the motive [end or final cause] is the principle [beginning or efficient cause] of action, holding the same place here that the hypotheses do in mathematics. 199 In mathematics, no reasoning or demonstration can instruct us about these principles or starting points; so here it is not reason but virtue, either natural or acquired by training, that teaches us to hold right opinions about the principle of action. A man of this character, then, is temperate, while a man of opposite character is profligate.