jective methods of science. Before proceeding to indicate what science has to say by way of positive construction, Metchnikoff applies his criticism of religion and philosophy to pessimism and optimism. Both religion and positive philosophy regard this present life as evil, but a future life as good. They are pessimistic as to present existence, but optimistic as to the life beyond the grave. The sceptical form of philosophy, to which a larger knowledge and the exact methods of science inevitably lead, destroys the optimistic outlook and brings man face to face with present life and that which scepticism takes to be the truth, viz., pessimism. Mankind, accordingly, appears to be placed in the following dilemma. Either cast aside reason and assuage the evils and sorrows of existence by passive endurance now and ungrounded hopes for the future, or follow reason, abjure will-o'-the-wisp beliefs, and endure without hope a meaningless and miserable existence. Science, however, frees man from the dilemma by cutting beneath it. Pessimism recognizes the disharmonies of life, but stands helpless before them. Optimism also recognizes the facts of disharmony, stands blindly before them, and is carried away, by the inner impulse of the desire to live, to inadequate and unintelligent conclusions. Science recognizes both the essential evils of human life and the dominant desire of man to overtop them. But it neither stands helplessly before them nor flies to impossible conclusions. It seeks to understand the character and origin of the evil as also to take practical measures for its removal. Viewed scientifically, evil has its origin in disharmony between the physical organism of man and his environment. This is accounted for by man's peculiar development. For man must be regarded in some senses as a monster. Arising as a sport in the biological world, his origin was probably sudden after the fashion of species whose possibility was foreseen by Darwin, but whose actuality was first demonstrated by De Vries. Man's variation consisted essentially in "a brain of abnormal size, placed in a spacious cranium." This variation enabled him to outdistance other forms of life, and laid the foundations of his wonderful historical development. The sudden advantage was at the same time a disadvantage. It too quickly put out of use certain structures of man's physical organism, and gave opportunity for a greatly enlarged exercise of function on the part of structures inadequately developed to their freer and more complex use. Once man has come to appreciate this fact, his life problem ceases to be a useless worrying over the actual fact of disharmony or a soothing of his pain by senseless palliatives which do not relieve. It becomes an active, aggressive campaign, the possibilities of which Pasteur has so brilliantly illustrated.
There remains, however, the final fact of death. How can science meet that fact and the stubborn development of the instinct to live? They appear to stand in irreconcilable antagonism. The difficulty cannot be resolved by the thought of a continuance of life after death. The fact that mind is a function of a physical organism, which inevitably decays and disintegrates, effectively disposes of any such conception. Science can accom-
