light of the principle of the correlation and conservation of forces, it means that one form of motion, called the antecedent, passes over, and is completely transformed into, another form of motion called the consequent.
b) Causation may mean the invariable sequence of consequent on antecedent, the antecedent being regarded as the essential condition, conditio sine qua non, of the consequent. Here the antecedent, although necessary to the consequent, is not identical with it. In this case the antecedent may be physical and the consequent psychical, or both antecedent and consequent may be psychical.
c) Causation may mean psychical, or efficient, causation. An efficient cause is something more than a condition essential to the effect. It denotes that which actually produces the effect, and still retains its own identity in the process, side by side with the effect.
Miss Ritchie, speaking of the weakness of present ethical discussion, says: "In no respect is this weakness more noticeable than in the vague and unsatisfactory treatment of determinism by many of our most brilliant writers, who, while they would never think of denying the necessity of reasoning from effects to causes in any other sphere of knowledge, yet hesitate to admit that natural antecedents alone are to be sought for in explanation of moral actions." Again she says: "It is a false antithesis which opposes liberty and determinism, as though a free action must be identical with an uncaused event. It is irrational to speak of any occurrence as though it sprang into existence of itself, unrelated to, and in independence of, all other physical and psychical phenomena." That Miss Ritchie regards this as a fair representation of the libertarian doctrine, must be inferred from the fact that the whole discussion is carried on with such an assumption as its basis. Fiske, who belongs to this same class of determinists, states the case more bluntly, but not differently, when he says: "Volitions, according to the opinion of the free-will philosophers, are the only phenomena that occur without a cause." On this ground, Miss Ritchie accuses libertarian writers of being unscientific. It is evident that she is using the term 'causation' in the sense of physical causation, at least so far as that means invariable sequence, and yet, as is usual with deterministic writers, the charge is made that libertarianism violates the law of causation. This is the spook that is always raised to order to drive timid souls from the camp of libertarianism back into that of determinism. Like the genie appearing from a small bottle in the Arabian Nights' stories, it rises into the heavens, crescit eundo, and
