or that we have not sufficient knowledge to enable us to say whether or not they are impossible. In any case, before accepting them, we are bound as honest men to demand evidence which may be thoroughly sifted. The sort of stuff which we usually get, when we ask for such evidence, will be instanced at a later stage.
(2) Again, to speak quite strictly, I do not know that anyone would care to draw a hard-and-fast line between what is 'functional' and what is 'organic.' These terms are extremely convenient, but we must remember that they are only terms. There is an oft-recurring danger, against which we all require to be continually on our guard, of falling into the old error of the realists. 'Animate and inanimate' (assuming that the recent claim to have demonstrated in metals a process of reproduction analogous to those observed in protoplasm is endorsed, as seems probable), 'genus and species,' 'animal and vegetable,' these and many others are eminently useful classifications, and the border line between each and its opposite varies from comparative precision to extreme vagueness. But in no case are they absolutely precise in the sense in which the distinction between an integer and a vulgar fraction is precise. And in the
