There are degrees of vitality in living things, whereas there are only degrees of complexity and delicacy and efficiency in mechanical contrivances. One watch differs from another in the perfection of its works, but not as two living bodies with precisely similar structure differ from each other in their hold upon life, or in their measure of vitality. No analysis possible to science could show any difference in the chemistry and physics of two persons of whom one would withstand hardships and diseases that would kill the other, or with whom one would have the gift of long life and the other not. Machines differ from one another quantitatively--more or less efficiency; a living body differs from a machine qualitatively--its efficiency is of a different order; its unity is of a different order; its complexity is of a different order; the interdependence of its parts is of a different order. Yet what a parallel there is between a machine and a living body! Both are run by external forces or agents, solar energy in one applied mechanically from without; in the other applied vitally from within; both suffer from the wear and tear of time and from abuse, but one is self-repaired and the other powerless in this respect--two machines with the same treatment running the same number of years, but two men with the same treatment running a very unequal number of years. Machines of the same kind differ in durability, men differ in powers of endurance; a man can "screw up his courage," but a machine has no courage to screw up. Science may be unable to see any difference between vital mechanics, vital chemistry, and the chemics and mechanics of inorganic bodies--its analysis reveals no difference; but that there is a difference as between two different orders, all men see and feel. Science cannot deal with fundamental questions. Only philosophy can do this. Science is only a tool or a key, and it can unlock only certain material problems. It cannot appraise itself. It is not a judge but a witness. Problems of mind, of character, moral, aesthetic, literary, artistic problems, are not its sphere. It counts and weighs and measures and analyzes, it traces relations, but it cannot appraise its own results. Science and religion come in conflict only when the latter seeks to deal with objective facts, and the former seeks to deal with subjective ideas and emotions. On the question of miracle they clash, because religion is then dealing with natural phenomena and challenges science. Philosophy offends science when it puts its own interpretation upon scientific facts. Science displeases literature when it dehumanizes nature and shows us irrefragable laws when we had looked for humanistic divinities. XI THE ARRIVAL OF THE FIT