It is not uncommon to hear it said that the Lockeian movement was all well enough for psychology, but went astray because it invaded the field of logic. If we mean by psychology a natural history of what at any time _passes_ for knowledge, and by logic conscious control in the direction of grounded assurance, this remark appears to reverse the truth. As a natural history of knowledge in the sense of opinion and belief, Locke’s account of discrete, simple ideas or meanings, which are compounded and then distributed, does palpable violence to the facts. But every line of Locke shows that he was interested in knowledge in its honorific sense--controlled certainty, or, where this is not feasible, measured probability. And to logic as an account of the way in which we by art build up a _tested_ assurance, a rationalized conviction, Locke makes an important positive contribution. The pity is that he inclined to take it for the whole of the logic of science,[40] not seeing that it was but a correlative division of labor to the work of hypotheses or inference; and that he tended to identify it with a natural history or psychology. The latter tendency exposed Locke to the Humian interpretation, and permanently sidetracked the positive contribution of his theory to logic, while it led to that confusion of an untrue psychology with a logic valid within limits, of which Mill is the standard example. In analytic observation, it is a positive object to strip off all inferential meaning so far as may be--to reduce the facts as nearly as may be to derationalized data, in order to make possible a new and better rationalization. In and because of this process, the perceptual data approach the limit of a disconnected manifold, of the brutely given, of the merely sensibly present; while meaning stands out as a searched for principle of unification and explanation, that is, as a thought, a concept, an hypothesis. The extent to which this is carried depends wholly upon the character of the specific situation and problem; but, speaking generally, or of limiting tendencies, one may say it is carried to mere observation, pure brute description, on the one side, and to mere thought, that is hypothetical inference, on the other.