The want of intellectual taste here displayed appears also in the view taken by Epicurus of the aim and business of philosophy. If among the Stoics the subordination of theory to practice was frequently felt, among the Epicureans this subordination was carried to such an extent as to lead to a depreciation of all science. The aim of philosophy was, with them, to promote human happiness. Indeed, philosophy is nothing else than an activity helping us to happiness by means of speech and thought. [1106] Nor is happiness, according to Epicurus, directly promoted by knowledge, but only indirectly in as far as knowledge ministers to practical needs, or clears away hindrances to their attainment. All science which does not serve this end is superfluous and worthless. [1107] Epicurus, therefore, despised learning and culture, the researches of grammarians, and the lore of historians, and declared it a piece of good fortune for simplicity of feeling to be uncontaminated by learned rubbish. [1108] Nor was his opinion different respecting mathematical science, of which he was wholly ignorant. [1109] The calculations of mathematicians, he maintained, are based on false principles; [1110] at any rate, they contribute nothing to human happiness, and it is therefore useless and foolish to trouble oneself about them. [1111] The theory of music and poetry he likewise found exceedingly irksome, although he took pleasure in music itself and the theatre; [1112] and rhetoric, as an artificial guide to eloquence, seemed to him as worthless as the show-speeches which are the only result of the study of it. The power of public speaking is a matter of practice and of momentary feeling, and hence the skilful speaker is far from being a good statesman. [1113] The greater part of logical enquiries fared no better in his judgment. Himself no logician, he set little store by logic. Definitions are of no use; the theory of division and proof may be dispensed with; the philosopher does best to confine himself to words, and to leave all the logical ballast alone. [1114] Of all the questions which engrossed the attention of Stoic logicians, one only, the theory of knowledge, was studied by Epicurus, and that in a very superficial way. [1115] Far greater, comparatively, was the importance he attached to the study of nature, [1116] but even natural science was deemed valuable not so much for its own sake as because of its practical use. The knowledge of natural causes is the only means of liberating the soul from the shackles of superstition; this is the only use of natural science. If it were not for the thought of God and the fear of death, there would be no need of studying nature. [1117] The investigation of our instincts is also of use, because it helps us to control them, and to keep them within their natural bounds. [1118] Thus the onesided practical view of philosophy which we have already encountered in Stoicism was carried by the Epicureans to an extreme length.