This lateral extension of abstract components of description is called abduction , and I hope the reader may see it with a fresh eye. The very possibility of abduction is a little uncanny, and the phenomenon is enormously more widespread than he or she might, at first thought, have supposed.

Metaphor, dream, parable, allegory, the whole of art, the whole of science, the whole of religion, the whole of poetry, totemism... the organization of facts in comparative anatomy-all these are instances of abduction, within the human mental sphere.

But obviously, the possibility of abduction extends to the very roots also of physical science, Newton’s analysis of the solar system and the periodic table of the elements being historic examples.

Conversley, all thought would be totally impossible in a universe in which abduction was not expectable.

Here I am concerned only with that aspect of the universal fact of abduction which is relevant to the order of change that is the subject of this chapter. I am concerned with changes in basic epistemology, character, self, and so on. Any change in our epistemology will involve shifting our whole system of abductions. We must pass through the threat of that chaos where thought becomes impossible.

Every abduction may be seen as a double or multiple description of some object or event or sequence. If I examine the social organization of an Australian tribe and the sketch of natural relations upon which the totemism is based, I can see these two bodies of knowledge as related abductively, as both falling under the same rules. In each case, it is assumed that certain formal characteristics of one component will be mirrored in the other.

This repetition has certain very effective implications. It carries injunctions, for the people concerned. Their ideas about nature, however fantastic, are supported by their social system; conversley, the social system is supported by their ideas of nature. It thus becomes very difficult for the people, so doubly guided, to change their view either of nature or of the social systems. For the benefits of stability, they pay the price of rigidity, living, as all human beings must, in an enormously complex network of mutually supporting presuppositions. The converse of this statement is that change will require various sorts of relaxation or contradiction within the system of presuppositions.

What seems to be the case is that there are, in nature and correspondingly reflected in our processes of thought, great regions within which abductive systems obtain. For example, the anatomy and physiology of the body can be considered as one vast abductive system with its own coherence within itself at any given time. Similarly, the environment within which the creature lives is another such internally coherent abductive system, although the system is not immediately coherent with that of the organism.

For change to occur, a double requirement is imposed on the new thing. It must fit the organism’s internal demands for coherence, and it must fit the external requirements of environment.

It thus comes about that what I have called double description becomes double requirement or double specification. The possibilities for change are twice fractionated. If the creature is to endure, change must always occur in ways that are doubly defined. Broadly, the internal requirements of the body will be conservative. Survival of the body requires that not-too-great disruption shall occur. In constrast, the changing environment may require change in the organism and a sacrifice of conservatism.