> Instead, a better model of rationality is that of
> discrete and fuzzy sets. Each set consists of
> diffrent sets of variables, weights ranges of values
> which are pre-set so to speak by congitive framing.
> The framing determines which variables are relevent in
> a particular situation and which ones are not, what
> the relative weights of the relevant variables are,
> what the relvenat rnage of variables on those
> variables are, which variable are tentative and which
> ones are firmly set, etc. Then, they solve the problem
> in a rational way , along the lines of the rat choice
> models, but only within that particular set or
> context. In a differnet situation or context, a
> different rationality applies. Consequently, the
> relationship between X and Y that is valid in one set,
> is not valid in another.
Where "relations" are "internal" any reasoning that makes use of "variables" in this sense will only be of limited applicability. It requires that the things treated as "variables" remain self-identical to the degree required by the reasoning. One thing plus another thing don't always make two things.
Whitehead makes this point as part of a criticism of the misidentification of "reason" with axiomatic deductive reasoning. His own ultimate conception of rationality is "phenomenological" in the sense of Husserl.
Keynes, who was also a student of Whitehead, accepts both this idea of "rationality" and the criticism of excessive reliance on axiomatic deductive reasoning that Whitehead bases on it. As I just tried to show, the political economy Keynes "took in with his mother's milk" (Marshall's) had already appropriated these insights.
He added to this a psychoanalytic understanding of the mistaken identification of "reason" with formal logic as "obsessional" and as, in consequence, largely immune to rational critique. It is consistent with this explanation that "reason" understood in this way is experienced as an "iron cage" and that economists are blind to the fact that Keynes does not share their assumptions about "being" and "human being".
What alternative explanation does your idea of "rationality" provide for the adoption by economists of the view that human thought, willing and acting have everywhere and always been "rational" in their sense. In particular, does it imply that John Nash's "Nobel Prize" winning view of human thinking, willing and acting is "rational" in your sense, just as "rational" as, say, Shakespeare's? How about the beliefs that constitute "Rapture Christianity"?
Ted