Individuality, conceived as a temporal development involves uncertainty, indeterminacy, or contingency. Individuality is the source of whatever is unpredictable in the world.

The utmost possible regarding an individual is a statement as to some order of probability about the future. Heisenberg's principle has been seized upon as a basis for wild statements to the effect that the doctrine of arbitrary free will and totally uncaused activity are now scientifically substantiated. Its actual force and significance is generalization of the idea that the individual is a temporal career whose future cannot logically be deduced from its past.

Classical science was based upon the belief that it is possible to formulate both the position and velocity at one time of any given particle. It followed that knowledge of the position and velocity of a given number of particles would enable the future behavior of the whole collection to be accurately predicted. The principle of Heisenberg is that given the determination of position, its velocity can be stated only as of a certain order of probability, while if its velocity is determined the correlative factor of position can be stated only as of a certain order of probability. Both cannot be determined at once, from which it follows necessarily that the future of the whole collection cannot possibly be foretold except in terms of some order of probability.

The application of scientific formulations of the principle of probability statistically determined is thus a logical corollary of the principle already stated, that the subject matter of scientific findings is relational, not individual. It is for this reason that it is safe to predict the ultimate triumph of the statistical doctrine.

This idea is that laws which purport to be statements of what actually occurs are statistical in character as distinct from so-called dynamic laws that are abstract and mathematical, and disguised definitions. Recognition of the statistical nature of physical laws was first effected in the case of gases when it became evident that generalizations regarding the behavior of swarms of molecules were not descriptions or predictions of the behavior of any individual particle. A single molecule is not and cannot be a gas. It is consequently absurd to suppose that a scientific law is about the elementary constituents of a gas. It is a statement of what happens when a large number of such constituents interact with one another under certain conditions.

The revolution in scientific ideas just mentioned is primarily logical. It is due to recognition that the very method of physical science, with its primary standard units of mass, space, and time, is concerned with measurements of relations of change, not with individuals as such.

The discovery that mass changes with velocity, a discovery made when minute bodies came under consideration, finally forced surrender of the notion that mass is a fixed and inalienable possession of ultimate elements or individuals, so that time is now considered to be their fourth dimension.

When we come to inanimate elements, the prevailing view has been that time and sequential change are entirely foreign to their nature. According to this view they do not have careers; they simply change their relations is space. We have only to think of the classic conception of atoms. The Newtonian atom, for example, moved and was moved, thus changing its position in space, but it was unchangeable in its own being. ... In itself it was like a God, the same yesterday, today, and forever.

The animating purpose of James was, on the other hand, primarily moral and artistic. It is expressed in his phrase, "block universe," employed as a term of adverse criticism. Mechanism and idealism were abhorrent to him because they both hold to a closed universe in which there is no room for novelty and adventure. Both sacrifice individuality and all the values, moral and aesthetic, which hang upon individuality; for according to absolute idealism, as to mechanistic materialism, the individual is simply a part determined by the whole of which he is a part. Only a philosophy of pluralism, of genuine indetermination, and of change which is real and intrinsic gives significance to individuality. It alone justifies struggle in creative activity and gives opportunity for the emergence of the genuinely new.

The intellect is at home in that which is fixed only because it is done and over with, for intellect is itself just as much a deposit of past life as is the matter to which it is congenial. Intuition alone articulates in the forward thrust of life and alone lays hold of reality.