tion at all, I expect the answer to present itself as a necessary truth to my mind. It would no more occur to me, at all events in the first instance, to seek help in deciding the point from such extraneous sources as history, biology, sociology, than to seek help from such sciences in multiplying two by three. Very different is the case when I try to apply this principle to practice. I am asked, let us say, to contribute towards such and such a charity. Taking into account only the net results, for good or for bad, which the charity produces, shall I best be conforming to the principle of doing as I would be done by, if I give or if I withhold? Here, as in scores of other applications of the abstract principles of ethics, it seems to me difficult to exaggerate the importance of history, biology, sociology, economics, and observation and experience generally. I should no more hope to settle by mere intuition these concrete questions of right and wrong, than I should hope to divine intuitively the profits on a sale of corn.
Yet natural and important as this distinction is, it seems to be entirely overlooked by a great proportion of ethical writers; while even those who show incidentally that they feel the distinction to exist, are not much given to insisting upon it. At the one extreme is the thorough-going intuitionist, who attempts to discern by intuition alone between right and wrong even in the concrete; at the other extreme is the physical philosopher of the more rabid type, who entirely rejects intuition and the method of introspection as delusive, and would rest everything in morals on the facts of physical science. Fancy an intelligent mathematician searching for the truths of pure mathematics elsewhere than in the depths of his own consciousness! The distinction to which I am drawing attention may be further illustrated by reference to the syllogism. No M is P; some S is M; therefore some S is not P. If we wish to know whether in the abstract this reasoning is valid, we settle the question by introspection. The answer is self-evident. But the moment we throw the syllogism into the concrete form—no metal is transparent; some gases are metals; therefore some gases are not transparent—we are brought into contact
