Bion's use of modern logic.

This paper introduces the reader to modern logic, more particularly the branch of logic called 'Model Theory', which is extensively used by Bion. Logic today is no longer described as the study of 'valid inference', but rather by the notion of consistency of beliefs. This central concern of the logician with consistency is also seen to be that of the psychoanalyst when he aims for eventual resolution of conflict between a patient's contradictory beliefs. Models are explained as the use of the already familiar to explain the unfamiliar, as when, for example, we invoke our familiar planetary system to understand the complex structure of the atom. In psychoanalysis we seek to find the old childhood models underpinning a patient's contemporary model of himself and others. Thus both Model Theory and psychoanalysis are interested in how we 'see the new in terms of the old'. Finally, the creation of models is assimilated to the integrative tendency of depressive activity and the dissolving or collapsing of models linked to paranoid-schizoid activity. As these two processes in the individual are linked by Bion we can see human beings as continually oscillating between creating and destroying models of their inner and outer worlds.