This still illustrates however the issues of rigour whether in the human, animate, or inanimate sciences. I would suggest that the handling of the issue by Laplanche and Pontalis is as scrupulous as any mathematician. It is the most authoritative reference dictionary of psychoanalysis.
But Freud was also deeply committed to science and some of his psychological ideas even have a form that is mechanistic (Mechanism being the most prestigious current of scientific thinking at the time). As I understand it "overdetermined" means multiply determined, even though Laplanche and Pontalis make finer distinctions. Freud was arguing that more than one factor may contribute to an outcome. eg the fact that we may have wet the bed till the age of 11 may be caused by a childhood trauma, but it may have been caused by other things as well.
Brad's wider view, coming from mathematics would be interesting. No-doubt some of the post-modernists philosophers have used mathematical and scientific concepts metaphorically in a loose way. But chaos theory, whose dramatic title comes from within the sober scientific community, claims a solid foundation in mathematics going back over a century.
Natural scientists are capable of idealism and fantasy as well as social scientists. String theory in cosmology has taken off with only a tenuous connection to empirical reality. As a cyncal arts man, I do wonder if it is not because it allows for a proliferation of mathematical models, generating one paper after another. It has now been replaced by membrane theory or m theory which looks as if it will be as productive of papers.
James Gleick in his book "Chaos" argues that in meterology the fifties and sixties were a time of great confidence that it was going to be possible to predict the weather much more closely. When in 1961 Lorenz left a few decimal places off the inputs to his computer model and got a completely different pattern, the idea of a single cause and a single effect crashed. The butterfly in the Amazon is part of the fable, but the reality has enormous economic implications. We really cannot easily foretell the weather, and we now know we probably will never be.
The reason is quite reliably expressed in the mathematical community as "determinate indeterminacy": certain equations with a small number of given (determinate) inputs produce not a single result but a) patterns which fluctuate normally within a certain range most of the time, but may occasionally flip into two or more phases or a totally different phase. Such equations include feedback terms as they are executed in successive time intervals. In this respect they have analogies with living systems or self-reproducing patterns like the weather. Until computers were developed it was not possible to model this.
Mathematicians like the odd bit of colour. Consider the sub-atomic particles named after a Lewis Carrol poem. But if the term chaos theory were dropped, a more sober term like "dynamical systems theory" would be used. This expects roughly repeating patterns often to be the result of the interaction of several variables. It is not unscientific in principle to take these analogies from closed (determinate) systems in which all the factors are defined at time zero, and try them out in psychological and social situations in the real world, where the inputs are not closed off from extraneous factors. Whether Freud was analysising individual psychology, or Althusser or indeed we, are analysing economics, it is not unscientific to say that phenomena are multiply determined. In fact it is in conformity with the universe as we grow up in it. The Althusserians are however rather "overdetermined" to emphasise the point, which once appreciated, seems rather obvious even though the maths is challenging.
Chris Burford
London