Theoretical Reason And Logic

Abstract

The primary object of Part I is to expound Keynes’s philosophy and to support the contention that it contains a distinctive theory of rationality. The next six chapters are therefore occupied with elucidating his philosophical framework and its main properties. Two other themes are also developed. Firstly, that despite certain subsequent remarks, Keynes never abandoned the main elements of his philosophical position. Though it may have slipped more and more from view under the weight of economics, philosophy nevertheless continued to support the edifice of his thought and to reassert itself in various ways whenever he turned to fundamental issues. The second theme is that there are significant differences between Keynes’s conception of rationality and that upon which Neoclassical theory is grounded, although sight should not be lost of certain common features.

… how splendid a prospect opens before the logician if he have but the hope of introducing order in the great province of rational but inconclusive thought which now resists him.

J.M. Keynes 1907

Really the most substantial joys I get are from the perception of logical arguments.

J.M. Keynes 1908

I have described probability as comprising that part of logic which deals with arguments which are rational but not conclusive.

J.M. Keynes 1921

It seems to me that economics is a branch of logic …

J.M. Keynes 1938

[Knox] was sceptical of most things except those which chiefly matter, that is affection and reason.

J.M. Keynes 1943¹