In the 3rd century A.D. we find the beginnings of what is known as neo-Platonism. A very typical passage in Gibbon’s _Decline and Fall_ (ch. xiii.) refers to the neo-Platonists as “men of profound thought and intense application; but, by mistaking the true object of philosophy, their labours contributed much less to improve than to corrupt the human understanding. The knowledge that is suited to our situation and powers, the whole compass of moral, natural, and mathematical science, was neglected by the new Platonists; whilst they exhausted their strength in the verbal disputes of metaphysics, attempted to explore the secrets of the invisible world, and studied to reconcile Aristotle with Plato, on subjects of which both these philosophers were as ignorant as the rest of mankind.” Although this passage is coloured by some of the peculiar prejudices of Gibbon it fairly represents a common attitude towards neo-Platonism and might equally apply to every religious movement the world has ever seen. The neo-Platonists were the result, we may say the inevitable result, of tendencies which had been at work ever since the age of Alexander and the widening of the mental horizon and the decay of interest in the old civic life. The older philosophers had endeavoured to produce efficient citizens; but under imperialist conditions efficient citizens were not so much wanted as obedient subjects. Through all this period there are very clear indications of the new trend of thought which assumes a more theological and philanthropic character, aiming at producing good men rather than useful citizens. The speculations of Philo the Jewish Platonist give very plain indications of these new tendencies as they appeared in Alexandria. He shows the monotheistic tendency which was indeed present in the older philosophers but now begins to be more strongly emphasized as philosophy becomes more theological in its speculations, though no doubt in his case this was largely due to the religion he professed. He expressed the doctrine of a One God, eternal, unchanging, and passionless, far removed above the world of phenomena, as the First Cause of all that exists, a philosophical monotheism which can be fitted in with the Old Testament but does not naturally proceed from it. The doctrine of an Absolute Reality as the necessary cause of all that is variable, something like the fulcrum which Archimedes needed to move the world, was one to which all philosophy, and especially the Platonic school, was tending. But, as causation to some extent implies change, this First Cause could not be regarded as directly creating the world, but only as the eternal source of an eternally proceeding emanation by means of which the power of the First Cause is projected so as to produce the universe and all it contains. The essential features of this teaching are, the absolute unity of the First Cause, its absolute reality, its eternity, and its