Formalism, Logic and Reality: A Keynesian Analysis.

It is the purpose of this paper to elaborate on the argument that formalism is non-neutral; analyses which today would be described as informal turn into something quite different when formalised. The reasons for non-neutrality refer to the choice of assumptions or axioms, the choice of method, the type of logic employed and closure. Focusing on the last three of these, the paper addresses the question of how to move from results obtained with formal methods under conditions of closure to the reality one is attempting to model. We explore the need for provisional closure to analyse open systems and for a range of methods to complement formal modelling in the attempt to understand the complex reality of an economic system. Copyright 2001 by Oxford University Press.