The method of the investigation, like that of all investigations, must be determined by the nature of the evidence. The special feature of the evidence which affects the method is, that it is ample in regard to the causes, and ample also in regard to the effects, but scanty in regard to the process of change. We have ample evidence in regard to the state of Greek thought during the ante-Nicene period. The writers shine with a dim and pallid light when put side by side with the master-spirits of the Attic age; but their lesser importance in the scale of genius rather adds to than diminishes from their importance as representatives. They were more the children of their time. They are consequently better evidence as to the currents of its thought than men who supremely transcended it. I will mention those from whom we shall derive most information, in the hope that you will in course of time become familiar, not only with their names, but also with their works. Dio of Prusa, commonly known as Dio Chrysostom, “Dio of the golden mouth,” who was raised above the class of travelling orators to which he belonged, not only by his singular literary skill, but also by the nobility of his character and the vigour of his protests against political unrighteousness. Epictetus, the lame slave, the Socrates of his time, in whom the morality and the religion of the Greek world find their sublimest expression, and whose conversations and lectures at Nicopolis, taken down, probably in short-hand, by a faithful pupil, reflect exactly, as in a photograph, the interior life of a great moralist’s school. Plutarch, the prolific essayist and diligent encyclopædist, whose materials are far more valuable to us than the edifices which he erects with them. Maximus of Tyre, the eloquent preacher, in whom the cold metaphysics of the Academy are transmuted into a glowing mysticism. Marcus Aurelius, the imperial philosopher, in whose mind the fragments of many philosophies are lit by hope or darkened by despair, as the clouds float and drift in uncertain sunlight or in gathered gloom before the clearing rain. Lucian, the satirist and wit, the prose Aristophanes of later Greece. Sextus Empiricus, whose writings—or the collection of writings gathered under his name—are the richest of all mines for the investigation of later Greek philosophy. Philostratus, the author of a great religious romance, and of many sketches of the lives of contemporary teachers. It will hardly be an anachronism if we add to these the great syncretist philosopher, Philo of Alexandria; for, on the one hand, he was more Greek than Jew, and, on the other, several of the works which are gathered together under his name seem to belong to a generation subsequent to his own, and to be the only survivors of the Judæo-Greek schools which lasted on in the great cities of the empire until the verge of Christian times.