neither imposes on the other a "must" that is not at the same time already the other's "would." In other words, any state in one is always the occasion, but, so far as an independent causation goes, the wholly passive occasion of something quite pertinent occurring in the other. Is there an idea, a state of consciousness; then, corresponding, there is some real thing, some physical object adequate to the idea. Is there an act of will; then, corresponding to it, some movement in the material world. Were the relation different from this, were mind and matter ever independent causes, not merely coincidents or perhaps co-operative causes, of each other, then, as is worth adding, besides the disturbance of the equivalence of reality, already referred to, there would be implied a fixity of plan, or manner of action, and a definiteness of possessed power in the nature of the supposed causes, and these implications would also give offence. Yet in the world of our journeying there must be causation--on some plan--of some sort. Parallelism, though sometimes supposed to be more sweeping, is really and consistently a denial only of isolated, independent causes. It denies, not causation, but causation as ever localized or with an exclusive residence. [p.207] In very much the same way certain political ideas, growing to explicit expression contemporaneously, have denied, not sovereignty or power, but an exclusively localized sovereignty or power, as in the case of absolute monarchy or of an absolute institution, whether church or state. Parallelism, or at least the inner meaning of it, simply imposes certain conditions on a still real causation. These conditions, too, necessarily involve a significant, even a revolutionary change in the nature and value of any cause, but beyond peradventure they are unavoidable conditions. Thus, every active thing having any part in the causation of the world must always be only one among other active things, each also with some part. Then, secondly, all active things must co-operate, in, if not actually through their differences working together and harmoniously for what is real. In short, they must be "parallel." And, lastly, as something not formally asserted by parallelism but still far from incongruous with it and, as seems to me, even demanded by its inner meaning, all active things must be always acted upon as well as acting.