The reader who desires to gain a thorough knowledge of Hellenistic philosophy, and of the social and political conditions in which it throve, will find what he seeks in two works to which I have to express my large indebtedness. One is Zeller’s _Philosophie der Griechen_ (_Epikureer_, _Stoiker u. Skeptiker_),[4] a monument of German research and erudition, in which vast masses of original material for the study of this most interesting, but neglected, epoch of the development of European intellect have been brought together, and interpreted with more than German lucidity and method. The other is Professor Mahaffy’s recent volume, _Greek Life and Thought_, a study of the Hellenistic period in various aspects, which the scholar will not read without profit, nor the lay-reader without pleasure. We turn now to that department of the Stoic philosophy with which the reader of Epictetus is most concerned—its Ethics. The ethical question resolves itself into a search for the supreme object of human endeavor, the _Summum Bonum_, the absolute and essential good. This, for the Stoic, embodied itself in the formula, “to live according to Nature.” But what is Nature? The will of God, as revealed in the heart and conscience of those who seek to know it, and interpreted through the observation in a reverent and faithful spirit of the facts of life. Going into the subject more precisely we find certain criteria of moral truth established, προλήψεις, as they were called, that is, primitive, original conceptions, or, as I have rendered them in my translation, “natural conceptions,” dogmas by which all moral questions can be tried. If we inquire into the source of these προλήψεις, we shall find ourselves mistaken in our disposition to think that the Stoics regarded them as innate ideas. Innate they are not, for the Stoics held the soul at birth to be a _tabula rasa_, or blank page, which only experience could fill with character and meaning. But as Seneca says in his inquiry, “Quomodo ad nos prima boni honestique notitia pervenerit,”[5] although Nature alone could not teach us these things, could not equip us with the knowledge of them before we entered upon life, yet the “seeds” of this knowledge she does give us; the soul of every man has implanted in it a certain aptness or, indeed, necessity to deduce certain universal truths from such observation and experience as are common to all mankind; and these truths, the προλήψεις, though not strictly innate, have thus an inevitableness and dogmatic force not possessed by those which one man may reach and another miss in the exercise of the ordinary faculties, by argument, study, and so forth. By these natural conceptions the existence and character of God, and the general decrees of the moral law, are considered to be affirmed. If we inquire further how the Stoic explained the fact that some of these so-called inevitable and universal conclusions are denied in all