As Huxley, on that great occasion, ascended the rostrum in the Sheldonian theatre, very white and frail in his scarlet doctor's robes, there must have been present in his mind memories of the occasion, four-and-thirty years before, when he first addressed an audience in the University of Oxford. Then he was a young man, almost unknown, rising to lead what seemed a forlorn hope for an idea utterly repugnant to most of his hearers. Now, and largely by his own efforts, the idea had become an inseparable part of human thought, and Huxley himself was the guest to whom the whole University was doing honour. Graduates from all parts of England had come to hear what, it was feared, might be his last public speech, and practically every member of the University who could gain admission was present. The press of the world attended to report his words as if they were those of a great political leader, about to decide the fate of nations. Although his voice had lost much of its old sonorous reach, and although the old clear rhythms were occasionally broken by hesitancies, the magic of his personality oriented to him every face. It is a curious and striking circumstance, a circumstance fully recognised by Huxley himself, that in this exposition of his ethical conception of the Cosmos he reconstructed, on the lines of his evolutionary philosophy one of the oldest and most widespread theories, a theory again and again reached by men of different civilisations and epochs. Manes, the Persian, from whose name the word "Manicheism" has been coined to denote his doctrine, taught in perhaps the most explicit fashion that the Cosmos was the battle-ground of two contending powers,--Ahriman, the principle of evil, and Ormuzd, the principle of good. This doctrine in some form or other is implicit in most of the greater religions, some of which have assumed an ultimate triumph for the principle of good, while others have left the issue doubtful. The Ahriman of Huxley, the principle of evil, is what he termed the cosmic process, that great play of forces, by which, in a ruthless struggle for existence, the fittest (by which is meant the most suited to the surrounding conditions and not necessarily the ethically best) have survived at the expense of the less fit. The Ormuzd, the principle of good, is what Huxley called the Ethical process, the process by which sentient, intelligent, and moral man has striven to replace the "old ape and tiger methods" of the cosmic process, by methods in which justice and mercy, sacrifice and consideration for others have a part.