For though the oldest philosophers of the Ionian school held water, or air, or fire, to be the ground and principle of all things, and built on such hypotheses their whole theory of nature, nevertheless we should, in all probability, greatly err, were we, on that account, to charge them with or to suspect them of materialism. They understood these elements, not in the ordinary, but in a spiritual and living sense, as the elements of universal life, and, at the same time, did not fail to acknowledge a higher spirit operating in and above nature, and God’s all-disposing intelligence. Of Heraclitus, who made fire the essential ground and first principle of all things, we know, with historical certainty, that, notwithstanding, his philosophy and view of the universe was, in the highest degree, ideal and spiritual. And the same is true also of Anaxagoras, the teacher of Socrates. Much, too, that would do great credit to the general spirit of thought and science of that period, might be adduced from the venerable founder of the valuable art of medicine, and also from his school, were the present the appropriate place. The simple fact, too, that Socrates proceeded from out of this Ionian school, would alone dispose me to form a favorable opinion of it in its earliest state; and it is greatly to be regretted that our information concerning the oldest of these great thinkers is so scanty, and its details so uncertain and so little to be depended on, that it is impossible to form any settled and definite judgment on the matter. When, however, we proceed to examine the religious spirit and value of Grecian philosophy in general, or any of its special branches, schools, and epochs, we must adopt as the fundamental rule of our judgment the universal dogmas of man’s pure and uncorrupted feelings or judgment. Taking for our standard the natural belief in a living and personal God, and in an everlasting and all-ruling spirit, in the immortality of the soul, and in the freedom of the will, together with the immutable principles and ideas of justice, honor, morality, and virtue, we must, in this case, carefully exclude all the special doctrines of a positive faith. We must not look for or require, in so early an age, that which the further development of later periods brought to light. Far be it from us to wonder at, or to urge it as a reproach against Pythagoras or Plato, if among their doctrines we meet with ideas, which, strictly understood, are not perfectly consistent with Christianity. Rather is it a matter for surprise and congratulation that they knew and were aware of, had anticipated and taught, so much that a later date first placed in a fuller light, and made the common property of all men. This, at least, was the opinion and conclusion on this subject entertained in the first century by the greatest and best-informed of the fathers of Christian doctrine and science.