149. The inference of cause with him is the inference from a change to something having power to produce it. [1] The value of this definition lies not in the notion of efficient power, but in that of an order of nature, which it involves. If instead of ‘something having power to produce it’ we read ‘something that accounts for the change,’ it expresses the inference on which all science rests, but which is as far as possible from being merely a transition from one event to another that usually precedes it. An event, interpreted as a change of something that remains constant, is no longer a mere event. It is no longer merely in time, a present which next moment becomes a past. It takes its character from relation to the thing or system of things of which it is an altered appearance, but which in itself is always the same. Only in virtue of such a relation does it require to be accounted for, to be referred to a ‘cause’ which is in truth the conception that holds together or reconciles the endless flux of events with eternal unity. The cause of a ‘phenomenon,’ even according to the authoritative exponent of the Logic which believes itself to follow Hume, is the ‘sum total of its conditions.’ In its fulness, that is, it is simply that system of things, conceived explicitly, of which there must already have been an implicit conception in order that the event might be regarded as a change and thus start the search for a cause. An event in time, apart from reference to something not in time, could suggest no enquiry into the sum of its conditions. Upon occurrence of a certain feeling there might indeed be spontaneous recollection of a feeling usually precedent, spontaneous expectation of another usually sequent. But such association of feelings can never explain that conception of cause in virtue of which, when accounting for a phenomenon, we set aside the event which in our actual experience has usually preceded it, for one which we only find to precede it in the single case of a crucial experiment. That we do so shows that it is not because of antecedence in time, however apparently uniform, that an educated man reckons a certain event to be the cause of another, but that, because of its sole sufficiency under the sum of known conditions to account for the given event, he decides it to be its uniform antecedent, however much ordinary appearances may tell to the contrary. Thus, though he may still strangely define cause as a uniformly antecedent event (in spite of its being a definition that would prevent him from speaking of gravity as the cause of the fall of a stone), it is clear that by such event he means one determined by a complex of conditions in an unchanging universe. These conditions, again, he may speak of as contingencies, _i.e._ as events contingent upon other events in endless series, but he must add ‘contingent in accordance with the uniformity of nature’--in other words, he must determine the