In this connection Epicurus shows his comprehensive grasp of the subject in determining what are the lasting pleasures. Although he was a materialist he regarded the pleasures of the mind as superior to those of the body. The inner pleasures, the spiritual joys, the control of the mind so that it could enjoy without indulgence――these were to Epicurus the enduring pleasures. The pleasures of sense are primary, for, in the last analysis, the mental life is a combination of sensations, and sensations are only material motions; nevertheless the secondary and derivative pleasures of the mind were superior, according to Epicurus, because they had duration. This estimate of the superiority of the mental pleasures was probably reinforced by two other reasons: such pleasures were possessed by Epicurus; and such a doctrine was in accord with the Greek æsthetic ideal of self-enjoyment of the refined egoist. The most permanent state of mind is called by Epicurus _independence of the world_, on the one hand, and _emotionlessness_, on the other. These are the positive and negative sides of one and the same thing――the Epicurean ideal of pleasure. In ancient times the conception of the “affections,” “passions,” or “emotions” included all states of feeling and will in which man is dependent on the outer world. To be emotionless is to be independent of the world. The Epicurean word is _ataraxia_, which is variously translated as serenity, peace, repose, imperturbability. Since man has no control over the world without him, he must control its effects within himself. These effects are the feelings and desires which are by nature only mental disturbances. In mastering these he becomes independent of the world.