The urgent problems of activity are thus more concrete. They all are problems of the true relation of longer-span to shorter-span activities. When, for example, a number of 'ideas' (to use the name traditional in psychology) grow confluent in a larger field of consciousness, do the smaller activities still coexist with the wider activities then experienced by the conscious subject? And, if so, do the wide activities accompany the narrow ones inertly, or do they exert control? Or do they perhaps utterly supplant and replace them and short-circuit their effects? Again, when a mental activity-process and a brain-cell series of activities both terminate in the same muscular movement, does the mental process steer the neural processes or not? Or, on the other hand, does it independently short-circuit their effects? Such are the questions that we must begin with. But so far am I from suggesting any definitive answer to such questions, that I hardly yet can put them clearly. They lead, however, into that region of panpsychic and ontologic speculation of which Professors Bergson and Strong have lately enlarged the literature in so able and interesting a way. The results of these authors seem in many respects dissimilar, and I understand them as yet but imperfectly; but I cannot help suspecting that the direction of their work is very promising, and that they have the hunter's instinct for the fruitful trails. APPENDIX C ON THE NOTION OF REALITY AS CHANGING In my _Principles of Psychology_ (vol. ii, p. 646) I gave the name of the 'axiom of skipped intermediaries and transferred relations' to a serial principle of which the foundation of logic, the _dictum de omni et nullo_ (or, as I expressed it, the rule that what is of a kind is of that kind's kind), is the most familiar instance. More than the more is more than the less, equals of equals are equal, sames of the same are the same, the cause of a cause is the cause of its effects, are other examples of this serial law. Altho it applies infallibly and without restriction throughout certain abstract series, where the 'sames,' 'causes,' etc., spoken of, are 'pure,' and have no properties save their sameness, causality, etc., it cannot be applied offhand to concrete objects with numerous properties and relations, for it is hard to trace a straight line of sameness, causation, or whatever it may be, through a series of such objects without swerving into some 'respect' where the relation, as pursued originally, no longer holds: the objects have so many 'aspects' that we are constantly deflected from our original direction, and find, we know not why, that we are following something different from what we started with. Thus a cat is in a sense the same as a mouse-trap, and a mouse-trap the same as a bird-cage; but in no valuable or easily intelligible sense is a cat the same as a bird-cage. Commodore Perry was in a sense the cause of the new régime in Japan, and the new régime was the cause of the