The question, Is the Platonic proof of the Divine existence substantially true? is precisely equivalent to the question, Is the Platonic philosophy substantially true? Of course, I cannot here attempt to argue a theme so vast as Spiritualism _versus_ Empiricism, Platonism _versus_ Positivism. My belief, however, is, that Platonism is substantially true; that the objections which the empiricism and positivism at present prevalent urge against its fundamental positions are superficial and insufficient; that what is essential in its theory of ideas, and in the theism inseparable from that theory, must abide with our race for ever as a priceless possession. The Platonic argument--by which is meant not a particular argument incidentally employed by Plato, but the reasoning which underlies and pervades his entire philosophy as a speculative search for certainty--has been transmitted from age to age down to the present day by a long series of eminent thinkers. Augustine, for example, argues for the existence of God from the very nature of truth. It is impossible to think that there is no truth. If there were none, to affirm that there was none would be itself true; or, in other words, the denial of the existence of truth is a self-contradiction. But what is truth? It is not mere sensuous perception, not a something which belongs to the individual mind and varies with its moods and peculiarities, but a something which is unsensuous, unchangeable, and universal. The human reason changes and errs in its judgments; but ideas, necessary truths, are not the products, but the laws and conditions, of the human reason--they are over it, and it is only through apprehending, realising, and obeying them, that it enlightens and regulates our nature. These ideas--the laws of our intellectual and moral constitution--cannot have their source in us, but must be eternally inherent in an eternal, unchangeable, and perfect Being. This Being--the absolute truth and ultimate ground of all goodness--is God. Anselm reasoned in altogether the same spirit and in nearly the same manner. In one of his works he institutes an inquiry as to whether the goodness in good actions is or is not the same thing present in all; and when he has convinced himself that it is the same thing, he asks, What is it? and where has it a real existence? Ascending upwards by these stages, Good _is_; Good is _perfect_; Good is _one_; the one perfect Good is God,--he comes to the conclusion that the goodness constitutive of good actions has necessarily its source in God, and that the absolutely and essentially good is identical with God. In another of his works he similarly inquires whether there is any truth except mere actual existence. He holds that there is, and argues, as he had done before in regard to the good, that the absolute and ultimate truth must be God. Thomas Aquinas was at one with Anselm thus far. The very nature of knowledge seemed to