The constant tendency with young students of philosophy, is to conclude that the hypotheses which they espouse with so much enthusiasm are new revelations in metaphysics and ethics as well as in physical science—­compared with which the Christian cultus of eighteen centuries is now effete and doomed.  It is well, therefore, to know that so far from these speculations having risen upon the ruins of Christianity, Christianity rose upon the ruins of these speculations as, in modified forms, they had been profoundly elaborated in the philosophies of Greece and Rome.  Lucretius was born a century before the Christian era, and Democritus, whose disciple he became, lived earlier still.  Kanada, the atomist philosopher of India, lived three centuries before Democritus.  The early Christian fathers were perfectly familiar with the theories of Lucretius.  We are indebted to Jerome for many of the facts which we possess concerning him.  Nearly all the great leaders of the church, from Origen to Ambrose, had studied Greek philosophy, some of them had been its devotees before their conversion to the Christian faith.  There is at least incidental evidence that the Apostle Paul was versed in the current philosophy as well as in the poetry of Greece.

These great men—­great in natural powers and in philosophic training—­had seen just what the speculations of Democritus, Lucretius, Zeno, Socrates, Plato, and Aristotle could do; they had indeed undermined the low superstitions of their time, but they had proved powerless to regenerate society, or even relieve the individual pessimism and despair of men like Seneca, Pliny, or Marcus Aurelius.  Lucretius, wholly or partially insane, died by his own hand.  The light of philosophy left the Roman Empire, as Uhlhorn and others have clearly shown, under the shadow of a general despair.  And it was in the midst of that gloom that the light of Christianity shone forth.  Augustine, who had fathomed various systems and believed in them, tells us that it was the philosophy which appeared in the writings and in the life of the Apostle Paul which finally wrought the great change in his career.  Plato had done much; Paul and the Cross of Christ did infinitely more.

The development of higher forms of life from lower by natural selection, as set forth by the late Charles Darwin, has been supposed to be an entirely new system.  Yet the Chinese claim to have held a theory of development which represents the mountains as having once been covered by the sea.  When the waters subsided small herbs sprang up, which in the course of ages developed into trees.  Worms and insects also appeared spontaneously, like lice upon a living body; and these after a long period became larger animals—­beetles became tortoises; worms, serpents.  The mantis was developed into an ape, and certain apes became at length hairless.  One of these by accident struck fire with a flint.  The cooking of food at length followed the use of fire, and the apes, by