With a clearer view of the facts, such doubt is seen to be inherently meaningless. Moreover, it follows from the above that pluralism, being expressed in terms of active selves, is truly explanatory for such active selves, i. e., for us. It thus differs in type from all hypotheses which are not expressed in such terms.
Although pluralism differs in type from other hypotheses, it is yet bound by certain limitations common to all hypotheses. An hypothesis passes from necessarily partial observations of a system to a description of the system as a whole in space and time, and is therefore inevitably fallible unless the system be assumed capable of complete description in general terms. Any system, however, comprising subjects of experience, is quite incapable of being so described, for the subjects, and the experience of each, are essentially individual and unique.
It follows from the above that, as we have at our disposal but limited observations of the world, it would be possible to find an infinite number of hypotheses descriptive of the world, which would sufficiently fit the narrow range of the observed facts. We could not form a unique and infallible hypothesis[1] unless we knew all the facts, past, present and future, and then it would no longer be an hypothesis, but a mere recital of those facts.
The fallibility of hypothesis is sufficiently illustrated by one fact alone, namely, that we have no reason at all to assume that laws which have held in the past will continue to hold in the future, unless we also assume some principle, such as that of induction, which depends on a priori principles of probability. Hence, though we may know an hypothesis to be false if it is contradicted by any fact, we can never certainly know it to be true. All that can be said is that it is more or less probable, the degree of probability depending on its applicability to the facts observed up to that time. Thus any final beliefs as to the constitution of the universe cannot depend on knowledge alone, but must be based on faith.
In selecting an hypothesis, then, we have a very great range of choice, for no hypothesis is ruled out of court till it fail to account for some fact, or rather, till it be definitely disproved by
- ↑ I.e., we could not be sure that it was infallible nor that it was the only hypothesis which would fit the facts.
