This sentiment leads us to the great maxim of Stoical Ethics, "Live according to Reason;" or, since the world is composed of matter and God, who is the Reason of the world, "Live in harmony with Nature." As Reason is supreme in Nature, it ought to be so in man. Our existence should be intellectual, and all bodily pains and pleasures should be despised. A harmony between the human will and universal Reason constitutes virtue. The free-will of the sage should guide his actions in the same irresistible manner in which universal Reason controls nature. Hence the necessity of a cultivation of physics, without which we cannot distinguish good from evil. The sage is directed to remember that Nature, in her operations, aims at the universal, and never spares individuals, but uses them as means for accomplishing her ends. It is for him, therefore, to submit to his destiny, endeavouring continually to establish the supremacy of Reason, and cultivating, as the things necessary to virtue, knowledge, temperance, fortitude, justice. He is at liberty to put patriotism at the value it is worth when he remembers that he is a citizen of the world; he must train himself to receive in tranquillity the shocks of Destiny, and to be above all passion and all pain. He must never relent and never forgive. He must remember that there are only two classes of men, the wise and the fools, as "sticks can only either be straight or crooked, and very few sticks in this world are absolutely straight." * * * * * [Sidenote: Rise of Greek science.] [Sidenote: Political position of the Ptolemies.] [Sidenote: They co-ordinate Egyptian idolatry and Greek scepticism.]