In the first half of the nineteenth century there were published at the cost of five thousand dollars apiece eight volumes known as the Bridgewater Treatises on "The Power, Wisdom and Goodness of God as Manifested in the Creation," using as illustrations the structure of the hand, the instincts of animals, the chemistry of digestion, and other unworked sources of natural theology. The science was not bad for its time, nor was the argument altogether fallacious. But the authors overlooked one thing, namely, that Bridgewater is a game two can play at, and that it would be equally possible to fill eight other volumes by picking out a different set of facts, almost equally imposing, to prove something very different, either that there is no God or that there is a devil, either atheism or Manicheism. Metchnikoff's "Nature of Man" supplies much of the material that a devil's advocate might then have used in his Anti-Bridgewater Treatises.
But Metchnikoff, writing in the twentieth century, makes quite another use of it. He has doubtless never read the Bridgewater Treatises, nor have many of us. There is no reason to now. They have become waste paper, not because they were false, but because the whole mass of the argument against them has vanished, the half recognized and subconscious argument against theism derivable from the undeniable existence of disharmonies and imperfections in the universe. This battlefield is deserted; though the same struggle continues, it is on higher ground. This change has been wrought by the introduction of the idea of evolution. We now realize we do not live in a static universe. The theism which is founded on evolution may serenely acknowledge the discords and failures which would be fatal to the theism of the Bridgewater era. And Metchnikoff, as an atheist, is equally untroubled by the existence of misleading instincts and useless, disease-producing organs, for interpreting them in the light of evolution he escapes the slough of nineteenth century pessimism and arrives triumphantly at the goal of optimism.
At least he says he does. I cannot see that his argument leads to optimism in the strict sense of the word, although it certainly leads him to a very sane and hopeful meliorism. The weakest point in his doctrine of orthobiosis seems to me his theory of euthanasia, that at the end of the "normal cycle" of life—whatever that may be—the desire for life is replaced by an instinct for death. The evidence he adduces in support of this is very scanty and questionable. It is curious to note that it was the experiences of Metchnikoff's brother which supplied Tolstoy with the material for the most harrowing picture of the fear of death in all literature, "The Death of Ivan Ilyitch"?
In "The Prolongation of Life" Metchnikoff devotes much space to an analysis of the first and second parts of "Faust" and the life of Goethe, whom he manifestly regards as an excellent example of a complete and well-ordered life. The reader will observe that while he condemns Goethe's drinking habits because they undermined his constitution, he has, from the standpoint of a naturalist, no word of blame for his promiscuous love affairs, since these contributed to the development of his genius. This is, to say the least, a very one-sided view to take of it.
But this volume is concerned with the exposition rather than the criticism of the authors discussed, so I will conclude the chapter with a quotation which sums up his philosophy and sets forth his ideals:
In progress toward the goal, nature will have to be consulted continuously. Already, in the case of the ephemerids, nature has produced a complete cycle of normal life ending in natural death. In the problem of his own fate, man must not be content with the gifts of nature; he must direct them by his own efforts. Just as he has been able to modify the nature of animals and plants, man must attempt to modify his own constitution, so as to readjust its disharmonies.
Breeders form a conception of the ideal result when they are about to attempt the production of some new variety which shall be pleasing æsthetically and of service to man. Next, they study the existing individual variations in animals and plants on which they wish to work, and from which they will select with minutest care. The ideal result must have some relation to the constitution of the organism selected. To modify the human constitution, it will be necessary, first, to frame the ideal, and thereafter to set to work with all the resources of science.
If there can be formed an ideal able to unite men in a kind of religion of the future, this ideal must be founded on scientific principles. And if it be true, as has been asserted so often, that man can live by faith alone, the faith must be in the power of science.—"The Nature of Man", p. 302.
HOW TO READ METCHNIKOFF
The philosophy of Metchnikoff is given in two volumes published in this country by Putnams, "The Nature of Man" and "The Prolongation of Life." The second and later volume will perhaps better serve the purpose of the general reader, but either will give the main outlines of his theories. Both volumes are written for the medical student rather than the public, and discuss some unpleasant subjects, but not in any objectionable manner. The English translation, at least in the first editions, is clumsy and careless. These works in the original are entitled "Essais sur la nature humaine", Paris, 1903, and "Essais optimistes", Paris, 1907. The German version, "Studien über die Natur des Menschen", Leipsic, 1904, is prefaced by Ostwald. "The New Hygiene", Three Lectures on the Prevention of Infectious Diseases, prefaced by Lankester, is published by W. T. Keever & Co., Chicago.
Articles by Metchnikoff easily accessible are: "Studies in Natural Death", in Harper's Magazine, Vol. CXIV, p. 272; "The Utility of Lactic Microbes", in Century, Vol. LXXIX, p. 53; "Old Age", in Smithsonian Report, 1904.