Page:Mind (New Series) Volume 6.djvu/398

 382 CRITICAL NOTICES: in the main, accepting nearly all his analyses of the purely noetic states of consciousness. Dissent such as this concerns matters whose full study would lead us far into the realms of the general logic and metaphysics of causation. I may premise, however, in general, that, to my mind, whoever says " Experience proves that A causes B " is logically committed to certain assertions both about the nature of the A and the B of which the relation in question is affirmed, and about the nature of the experience to which the assertor of the proposition appeals. And these assertions are in substance as follows : First, A and B have to be conceived as facts of a universally verifiable, of a public, of a socially tested character and type. Physical facts are conceived as of this character, namely, as common objects for many possible observers. Secondly, the experience to which one appeal's, as proving the causal relation, is not the experience of any one observer as such, but a certain conceived common experi- ence of scientific observers in general. In consequence of this logical condition of the very conception of a causal connexion, I conceive that no observer can say : "I have in trospectively dis- covered a causal connexion existent within my consciousness ". This assertion as to the logical significance of the conception of causation will doubtless call forth objection. I have no time to defend it at length here. I can only say, in brief, that I hold it because it seems to me that the whole history of the explanation of nature by men warrants this definition. Explanation of nature has always been a social affair. Men have taught one another to think about nature. The categories of human thought about nature are consequently ethnological products. In particular, the spirit of natural science grew out of two essentially social sources : the first w r as the commercial spirit, which taught men exactness in the definition of facts, and especially in the quantitative defini- tion of facts, since commerce, as a social process, forced men to measure and weigh goods, and to define contracts ; the second was the spirit of industrial art, whose traditions, in order to be passed on from generation to generation, demanded exactness in the definition of processes. Now both commerce and art deal with socially com- mon objects, in so far as they are common. And both the indus- trial and the commercial spirit require the agreement of various men about facts conceived as common to them all, and, therefore, as relatively independent of any one of them. The things bought and sold, the contracts executed, the processes of an art taught by the master to the apprentice, are all viewed as exact, as definable and as subject to law, precisely in so far as they are also mat- ters of tradition, of agreement, of social community. Thus first developed the conception of fact subject to natural law. The exactness of the law was the obverse aspect of its socially common character. The conception still bears the marks of its origin. Science inherited and developed this conception. As a fact, no student of physical science conceives natural fact as properly the