Patterning uncertainty: partial likeness, analogy and likelihood1

This paper examines the role of similarity judgements in Keynes’s theory of analogy as discussed in the Treatise on Probability (Keynes, 1921) and outlines a conceptual framework in which induction by analogy based on the identification of partial resemblances leads to likelihood as the central disposition by which human actors assign a pattern to uncertainty. The structure of the paper is as follows. Section 2 discusses Keynes’ view of analogy as the foundation of inductive inference. Section 3 outlines a theory of similarity based on Keynes’s criteria of finite variety and negative analogy. Section 4 highlights the relationship between a similarity-based theory of induction and Keynes’ ontological view that similarity features derive from a finite number of ‘generator properties’. Section 5 examines the social structuring of similarity features and the active role of agents in constructing the inductive knowledge of the world they inhabit. Section 6 brings the paper to close by calling attention to the relationship between dispositions, circumstantial visualisation of similarity features and problem-solving actions in the world of practice.