I note this statement of Professor Thomson's chiefly because it illustrates a very common method of dealing with the mechanistic or non-theistic view of the universe. In this matter Professor Thomson may claim the companionship of Sir Oliver Lodge, who says, "Materialism is appropriate to the material world, not as a philosophy, but as a working creed, as a proximate, an immediate formula for guiding research. Everything beyond that belongs to another region, and must be reached by other methods. To explain the psychical in terms of physics and chemistry is simply impossible.... The extreme school of biologists ... ought to say, if they were consistent, there is nothing but physics and chemistry at work anywhere." With both these writers there is the common assumption that the mechanist assumes there is a physical and chemical explanation of all phenomena. And the assumption is false. There is a story of a well-known lecturer on physiology who commenced an address on the stomach by remarking that that organ had been called this, that, and the other, but the one thing he wished his students to bear in mind was that it was a stomach. So the mechanist, while firmly believing that there is an ascending unity in all natural phenomena, is never silly enough to deny that living things are alive, or that thinking beings think. But unless Professor Thomson does impute this to the mechanist, we quite fail to see the relevance his assertion that there are three departments, physics, biology, and psychology, each with its characteristic questions, categories, and formulae. Of course, there are, and equally, of course, physical laws will not cover biological facts; nor will biological laws cover psychological ones. This is not due to any occult cause, but to the simple fact that as each group of phenomena has its characteristic features, each set of laws are framed to cover the phenomena presented by that group. Otherwise there would be no need of these special laws. It is astonishing how paralysing is the effect of the theistic obsession on the minds of even scientific men, since it leads them to ignore what is really a basic consideration in scientific method.