Introduction

It is not my intention to propose yet another interpretation of Keynes's General Theory. I shall concentrate exclusively on one very limited aspect of his mature work: the logical scheme of the arguments developed in the General Theory, which may be called his ‘heuristic model’. This scheme, expressed in ‘semi-formalized’ language, consists of a causal ‘plot’ and a set of ‘instructions for use’ which remain partly implicit.

It will be useful to begin with a reconstruction of the causal links that make up the basic structure of the heuristic model and of the whole General Theory. In chapter 121 shall deal more specifically with the ‘instructions for use’ and the underlying ‘conception of economic science’.

Keynes sees macroeconomics as a discipline based on probabilistic arguments which aim to persuade a rational audience. These arguments are ordered sets of propositions, whose structure is dictated by links of epistemic probabilistic causality (see chapter 7).

At first sight the causal structure of the heuristic model, in the version here proposed, will look very much like that of the analytic models used in textbooks to illustrate Keynes's theory. Thus my exposition might at first seem pointless, but it aims to emphasize certain peculiarities of Keynes's contribution which, despite their considerable importance, are traditionally neglected. In addition the following exposition will help to bring out what in my view is the meaning, as well as the theoretical and empirical value, of the Keynesian method.