and to proclaim that this mechanical theory was after all but an abstract and ideal scheme — a pure science, which can only be actually ‘applied,’ as we say, with the help of the calculus of probabilities. And what diversity and irregularity the seeming simplicity and uniformity of large numbers may cover human statistics sufficiently show. In place then of the concrete world of sense symbolising this abstract scheme, it has now become clear that it is the abstract scheme itself which symbolises the concrete world from which it set out. It also indeed reveals the law and order that there prevail; but what the concrete world really is and what is the source of the law and order that it manifests are questions still wholly on our hands. But to call such descriptive scheme pure or rational science is to emphasize its source in mind; and when this intelligible scheme of our devising, with which the scientific inquirer greets Nature, is confirmed by Nature’s response, are we not justified in concluding that Nature is intelligent or that there is intelligence behind it?
When however the physical realists — those I mean who regard the mechanical theory not as an abstract summary of Nature’s routine but as presenting fully-orbed reality — when these realists are called upon to explain the relation of this mechanism to mind they become involved in hopeless inconsistencies. The mechanism is by definition an absolutely closed system, determinate in all its movements down to the minutest detail. Not merely does it brook no interference, but interference is strictly speaking inconceivable: the semblance of such could only mean the presence of