However simple this state of things may be to a purely rational being, it must be remembered that man is not purely rational. [572] He has, therefore, irrational as well as rational impulses. [573] He is not originally virtuous, but he becomes virtuous by overcoming his emotions. Emotion or passion [574] is a movement of mind contrary to reason and nature, an impulse transgressing the right mean. [575] The Peripatetic notion, that certain emotions are in accordance with nature, was flatly denied by the Stoics. [576] The seat of the emotions—and, indeed, of all impulses and every activity of the soul [577]—is man’s reason, the ἡγεμονικόν. [578] Emotion is that state of the ἡγεμονικόν in which it is hurried into what is contrary to nature by excess of impulse. Like virtue, emotion is due to a change taking place simultaneously, not to the effect of a separate extraneous force. [579] Imagination, therefore, alone calls it into being, as it does impulse in general. [580] All emotions arise from faults in judgment, from false notions of good and evil, and may therefore be called, in so many words, judgments or opinions; [581]—avarice, for instance, is a wrong opinion as to the value of money, [582] fear is a wrong opinion as regards future, trouble as regards present ills. [583] Still, as appears from the general view of the Stoics respecting impulses, [584] this language does not imply that emotion is only a theoretical condition. On the contrary, the effects of a faulty imagination—the feelings and motions of will, to which it gives rise—are expressly included in its conception; [585] nor is it credible, as Galenus states, [586] that this was only done by Zeno, and not by Chrysippus. [587] The Stoics, therefore, notwithstanding their theory of necessity, did not originally assent to the Socratic dictum, that no one does wrong voluntarily. [588] Younger members of the School may have used the dictum as an excuse for human faults, [589] fearing lest, in allowing freedom to emotions, they should admit that they were morally admissible and give up the possibility of overcoming them. [590] Nay more, as all that proceeds from the will and impulse is voluntary, [591] so too emotions are also in our power; and it is for us to say, in the case of convictions out of which emotions arise, as in the case of every other conviction, [592] whether we will yield or withhold assent. [593] Just as little would they allow that only instruction is needed in order to overcome emotions; for all emotions arise, as they say, from lack of self-control, [594] and differ from errors in that they assert themselves and oppose our better intelligence. [595] How irregular and irrational impulses arise in reason was a point which the Stoics never made any serious attempt to explain. [(b) Varieties of emotion.]