> Its long been recognised that mathematical theory, due to its very
> nature,
> tends to become a language operating without reference to reality. I
> remember the psychoanalyst Jacques Lacan went as far as to compare
> maths to
> chronic psychotic variants of mental illness, such as paranoid
> schizophrenia, insofar as both construct their own reality without
> reference
> to externalises.
I don't know about Lacan, but the version of psychoanalysis developed by Melanie Klein provides an explanation of the inappropriate use of math as an obsessional defense against paranoid anxiety (the form of anxiety she identifies with the "paranoid-schizoid position" and links to paranoid schizophrenia).
Most economists (along with many others) can't see why a paranoid schizophrenic, i.e. someone given to psychotic delusions about motives, is incapable of what's really required for truly "scientific" social theory, namely, the capacity for insight into motives found in the best literature, e.g. in Shakespeare and Balzac.
Keynes provides both (1) an explanation (based on the ontological, anthropological and psychological ideas he claims provide the appropriate framework for social theory - the most important of them, from this perspective, being the ontological idea of "internal relations") of the limited applicability of axiomatic deductive reasoning in general and mathematical reasoning in particular in economics and (2) an explanation, in terms of the psychoanalysis of obsessional neurosis, of the immunity of those who uncritically identify "science" - including "social science" - with such reasoning to rational critique.
I've several times pointed on this list to A.N. Whitehead's explanation of why "internal relations" limit the applicability of axiomatic deductive reasoning. e.g. <http://mailman.lbo-talk.org/2007/2007-January/001418.html
>.
Ted