552 W. L. DAVIDSON : of the causal law in the sphere of volition. The question of range is altogether a separate problem, and must not be mixed up either with that respecting the import of the notion or with that respecting the meaning and mode of expressing the prin- ciple. Here, then, are no fewer than five questions (or sets of ques- tions) all relating to the same subject, yet each distinct and pos- sessing a value and position of its own. Nor can we, from knowing a writer's solution of one of them, infallibly divine his real attitude in relation to the remainder. Many, like Aristotle and the ancients generally, never handled the principle or law at all : it was mainly in the Latin world that there rose a clear view of the notion. Many, again, like Locke, have accepted the Ciceronian de- finition of the notion ("A cause is an efficient: we are not, there- fore, to conceive of it as though it were a bare antecedent, but as an efficient antecedent "), while they have traced its origin to "the notice that our senses take of the constant vicissitude of things " ; in other words, to experience of the world without us. Many, like Cousin, find the origin of cause in self-conscious- ness or will, while they regard the principle as something existing from the first potentially in the mind, to be afterwards called forth by experience. And many preach the influence of motives in determining action with all the vigour of Necessitarians, who yet refuse to admit that cause and motive are generically the same. The confusion, indeed, is something appalling, and is not equalled perhaps in any other province save that of Perception. The requirements of logical method have been lamentably neglected, and the resulting inconsistencies and incoherence are simply inevitable. Eeference has just been made to Perception. Well-trodden ground need not be re-traversed ; but two errors are particularly rife at the present moment, a brief allusion to which may not be inappropriate. One is, the mixing up of the problem of external perception with that other and entirely different problem as to the constitution of the human mind ; and the other has reference to the Experientialist's idealism and his philosophical method. As to the first of these, it is common enough to find the ques- tion of external perception argued as though it were the question of Spiritualism versus Materialism ; and the result is simply that which might be expected. "What is the essence of Mind?" is an inquiry of the utmost interest and importance ; but determine it in any way you please, and we have not thereby solved the question of Perception ; while, on the other hand, our solution of this does not necessarily implicate one particular view of Mind, and the attempt to render the implication necessary is fraught with baneful consequences. So with the second point. The Physicist and the Experiential Idealist (we are told, and told correctly) are to be classed together; for the method of the one is the method of the other, and the
