=171.= Under the general heading of Physics the ancients included a number of subjects which in modern times form independent branches of philosophy. Cleanthes subdivided the subject into Physics proper and Theology[1]. Here it will be convenient to make a larger number of subdivisions, so as to treat separately of (i) the Foundations of Physics, generally called (after Aristotle’s treatise) ‘Metaphysics’; (ii) Physics proper, that is, the account of the Universe and its history; (iii) the final problems involved in the history of the Universe, such as its government by Divine Providence, the Existence of Evil, Free-will, and Chance; (iv) the problems of Religion, such as the existence of gods, their number, character, and claims on mankind; and (v) the nature of Man, including the modern subjects of Psychology and Physiology, and to some extent of Anthropology also, treated by the Stoics as a Kingdom governed by the Soul. According to Stoic principles these subjects cannot be separated one from the other, or from the other parts of philosophy; and therefore in treating each one we shall, as before, assume a general knowledge of all the others. The Stoics laid great stress upon the study of Physics, as the only sound basis for a scientific rule of human conduct; and some of them (beginning with Chrysippus), having especial regard to the elevated dignity of the study of Theology, were disposed to rank this branch of philosophy as the highest and last of its three principal divisions[2]. We shall however, in accordance with a view more generally held, reserve the last place for Ethics[3]. [Sidenote: Fundamental Conceptions.]