Finally, as for life's origin and life's ultimate end, we are content to say that they are unknown, perhaps unknowable. We know only that living matter, like lifeless matter, has its own place in the cosmic processes; that the gigantic forces which operated to produce a world upon which life could exist, as a logical sequence, when the time was ripe, evolved life; and finally that these cosmic forces are still active, though none can tell what worlds and what races may be the result of their coming activities. A MECHANISTIC THEORY OF DISEASE[*] [*] Oration in Surgery. Delivered at the 147th Annual Meeting of the Medical Society of New Jersey, at Spring Lake, N. J., June 11, 1913. In this address the paragraphs which were taken from the preceding paper, "A Mechanistic View of Psychology," have been omitted, those portions only being republished in which the premises have been applied in a discussion of certain medical problems rather than of psychological problems. The human body is an elaborate mechanism equipped first for such conflict with environment as will tend to the preservation of the individual, and second for the propagation of the species, both of these functions, when most efficiently carried out, tending to the upbuilding and perfection of the race. From the date of Harvey's discovery of the circulation of the blood, to the present day, the human body has been constantly compared to a machine, but the time for analogy and comparison is past. I postulate that the body is itself a mechanism responding in every part to the adequate stimuli given it from without by the environment of the present and from within by the environment of the past, the memory of which is stored in the central battery of the mechanism-- the brain. * * * * * * * * * * * * * * * * * * * * If the full history of the species and of the individual could be known in every detail, then every detail of that individual's conduct in health and disease could be predicted. Reaction to environment is the basis of conduct, of moral standards, of manners and conventions, of work and play, of love and hate, of protection and murder, of governing and being governed, in fact, of all the reactions between human beings--of the entire web of life. As Sherrington has stated, "Environment drives the brain, the brain drives the various organs of the body," and here we believe we find the key to a mechanistic interpretation of all body processes.