reached.

This is more likely to be true when our emotions are involved. If a storekeeper has been robbed and there are five or six impressive circumstances which all suggest a certain clerk as the culprit, he may jump to the conclusion that the clerk is guilty, although he is perfectly aware of some other circumstance, which is less striking, but which is nevertheless absolutely incompatible with the clerk's guilt. If this circumstance is mentioned and the storekeeper is forced by it to admit that the clerk is not guilty there is considerable chance that he will admit it very reluctantly, and will still feel that he nearly did it', and bear him a grudge accordingly. The good reasoner, whether he be a scout finding a trail, a detective tracing a crime, a physician diagnosing a case, or a scientist pure and simple, is the one who has not only skill enough to observe the less striking circumstance but strength enough to hold it in mind until it is accounted for, instead of allowing it to be swept away like the still small voice of conscience by the larger mass of more vigorous impressions and associations that hurry us on to a more apparent goal.

Even in the aspect of a situation that we really do attend to we may overlook the necessity for explaining the finer details. Every one knows in a general way that rough water is caused by wind; but when we have accounted for this general appearance of roughness most of us are satisfied. As Professor Huxley says: " Even thoughtful men receive with surprise the suggestion" that the form of every wave and the direction taken by every particle of foam are the exact effects of definite causes"; and so long as we fail to recognize this precision of the causal relation it is perfectly evident that we do not realize the complete uniformity of

nature.

Thus while it is absolutely necessary that we should ignore certain aspects of a situation when we try to explain others, it is quite as necessary that we should not ignore the wrong ones. The only thing to do under these circumstances is

first to make an explanation that will account for the aspect of the situation in which we are interested and then to inquire in a cold-blooded, critical way whether there are not other aspects of the situation with which the explanation is not consistent. If there are we must reject it even though it has cost us years of labor. It may be that every one has a lurking tendency to feel that a plausible explanation has some value, whether it be true or not, until it is proved to be false. But-except as it helps us to remember the facts themselves-it has not, and the sooner we recognize its falseness and try to find one that will stand in spite of criticism, the better it is for ourselves and everybody else. It is useless to try and live in a fool's paradise or to bury our heads in the sand and refuse to recognize the disagreeable facts that upset our theories.

Besides the necessity for looking at one aspect of a situation at a time there is another reason why it is hard to realize that every event "is the exact effect of definite causes"; namely, because it is hard to realize that the events themselves are exact and definite. Most of our ideas are very hazy, and it takes hard training to make us realize that the realities which these ideas profess to represent are not as hazy as the ideas themselves; that though we can form no clear idea of the beginning of things, there was no chaos, no mere 'stuff' without definite attributes and relations; and that though we may be in doubt about some state of affairs, there is no uncertainty or hesitation in the state of affairs itself. Hazy thoughts claim to represent reality as much as clear ones, and so long as all our thoughts are hazy we cannot realize that the claim is false. We must know some realize that all things.

things definitely before we can begin to

are definite whether we know them definitely or not. Whenever we have used exact measurements so often that we feel the tendency to apply them to everything and no description seems complete without accurate statements about size, shape, direction, number, duration, degree, and

so on, we are then in a position to realize that these quantitative relations of things fit into the general law of uniformity as well as the qualitative. Then, but hardly any sooner, do we realize that the form of every wave and the path of every falling leaf are the exact effects of definite causes'; that the law of uniformity is not only universal but precise.

thing-aspect

To realize the uniformity of nature it is quite as necessary to keep a clear view of the individuality or separateness of different things as to make clear distinctions between different circumstances. Yet this abso- The lute distinction between different things we often of this precision. tend in our instinctive reactions to ignore. If we are stung by one hornet it seems appropriate in revenge to wipe out the entire nestful, whether it includes the one that hurt us or not. If certain Americans are massacred by a set of Chinamen in Asia it is perfectly natural for a mob of other Americans to revenge itself by attacking some innocent laundryman in Kansas City. If two or three members of a household do us an injury it is difficult, especially if we are not brought into close contact with them, not to harbor resentment against the whole household. To the individuals themselves the difference between them may mean everything; to us it means nothing at all.

In much the same way as we ignore the numerical difference between several individuals and treat one as though in some way it were actually identical with another because it belongs to the same group, so we ignore also the distinction between different kinds of individuals. To make an accurate definition is one of the hardest things in the world; but the curious thing is that it often comes to people as a sort of revelation that such definitions can be made at all. Definition is possible!' This thought it was, perhaps more than any other, which gave Socrates a life-long inspiration. But to assert the possibility of definition—to say that some moral attribute or some material thing can be defined in such a way as to include by the very definition all that we think

the word should stand for, and to exclude all that we think it should not-is only another way of saying that whether we can find it or not the difference between things or kinds of things is always perfectly definite.

In still another way uniformity of nature involves more about things than is evident at first. It involves the absolute permanence of whatever can truly be called a Thing. People often suppose that when things are burned up' the total amount of matter or of ultimate things in the world is diminished and that when plants grow it is increased. But such a supposition is inconsistent with the very idea of a thing and with all our explanations of events that involve it. When we say that some given event is due to the circumstances in which certain things were placed, we take it for granted that the things existed before the circumstances, and were thus at least relatively permanent; and when we learn that the permanence of sticks and stones and other such things by which we have explained events is not absolute, we account for it by saying that after all they are not really things at all in the ultimate sense of the word, but only temporary combinations of atoms, which latter are truly permanent; and that these atoms are the true things. Thus we come to realize what the scientists call the conservation of matter. The permanence of things is one of the two great aspects under which we think of the general law of uniformity in the world; and to assume that any real thing is not permanent is therefore to deny the existence of absolute | uniformity. Yet it is difficult to realize in a positive way [] that the law of uniformity implies the absolute permanence of every ultimate 'thing'. This scientific principle of the conservation of matter (and of any other ultimate reality) states for the things involved the same absolute uniformity that the law of absolutely precise causation states for the circumstances in which they are placed.

Thus far we have explained how we grow into the belief that Nature is uniform, and we have shown the forms which i

uniformity.

we expect that uniformity to take; and yet after all we have not proved that such uniformity exists, and it is the Proof of proof of facts and not the history of beliefs with which we are concerned in logic. But where would such proof begin? If we do not take uniformity of any sort for granted we should have to begin like Descartes by pretending to doubt our own existence and the existence of other people to whom the proof might be addressed, for even personal identity is a principle of uniformity; and we should assuredly share in Descartes' failure. If, on the other hand, we are willing to be less thoroughgoing than Descartes and take something for granted to begin with, and thus begin our attempted demonstration with the assumption that there are things and that various uniformities have existed in the past, why is this any evidence that other kinds of uniformity exist now or that any whatever will exist in the future,—unless we already take for granted some wider principle of uniformity which decrees that if uniformity exists anywhere or at any time it must exist everywhere and always? The fact that the sun. has risen (as we believe) every twenty-four hours throughout long ages makes us expect that it will rise to-morrow; but unless we already assume that the future will resemble the past it does not prove it.

Possibly the best thing that any one can say in justification of his conviction that experience depends upon a world of uniform relations is merely this: that it is a faith growing out of his very nature as an active being (if he exists and has a nature), that he has lived by it in the past (if he has had a past), that the longer he has taken it for granted the more it has seemed to justify itself, and that he means to take it for granted in the future (if there is a future). belief in the uniformity of things is thus something which we can account for psychologically, and we can show that to deny this uniformity in toto involves conclusions which no sane man is willing to act upon; but there is no direct way of proving its existence.