The Holmesian logician: Sherlock Holmes\u2019 \u201cScience of Deduction and Analysis\u201d and the logic of discovery

Emmanuel J Genot

doi:10.1007/s11229-020-02709-w

Abstract

This paper examines whether Sherlock Holmes’ “Science of Deduction and Analysis,” as reconstructed by Hintikka and Hintikka (in: Eco U, Sebeok TA (eds) The sign of three: Peirce, Dupin, Holmes, Indiana University Press, Bloomington, 1983), exemplifies a logic of discovery. While the Hintikkas claimed it does, their approach remained largely programmatic, and ultimately unsuccessful. Their reconstruction must thus be expanded, in particular to account for the role of memory in inquiry. Pending this expansion, the Hintikkas’ claim is vindicated. However, a tension between the naturalistic aspirations of their model and the formal apparatus they built it on is identified. The paper concludes on suggestions for easing this tension without losing the normative component of the Hintikkas’ epistemological model.

Highlights

In the fictional universe Sherlock Holmes inhabits, logicians are capable of astounding feats that seem well beyond the abilities of their real-world counterparts
In 1877, doctor-in-training Arthur Conan Doyle served as an assistant to Scottish surgeon Joseph Bell (1837–1911) at the Royal Edinburgh Infirmary
We examine how much the Hintikkas captured of Holmes’ “Science of Deduction and Analysis” and whether their reconstruction qualifies as a logic of discovery

Summary

Introduction

In the fictional universe Sherlock Holmes inhabits, logicians are capable of astounding feats that seem well beyond the abilities of their real-world counterparts. We examine how much the Hintikkas captured of Holmes’ “Science of Deduction and Analysis” and whether their reconstruction qualifies as a logic of discovery. The inquiry terminates when this ‘big’ question receives a conclusive answer, that is, when Holmes and the other parties involved all agree that a given individual, object, or location, satisfies the definite description. Sherlock Holmes’ ‘big’ question is answered when there is a deductive proof that such and such individual satisfies the definite description occurring in the ‘big’ question, based on whatever premises end up being accepted by the parties involved in the investigation at the end of the inquiry. Hintikka and his collaborators abandoned utilities and characterized the relation between deduction and interrogation with the resources of first-order semantics and proof theory alone Let us have a closer look at how the Hintikkas integrate questions within proofs

The limits of analysis and the role of memory

Holmes’ “brain attic” as a strategic account of memory

The neuroscience of the brain attic

The reconstruction of association-based reasoning

Holmesian inquiry and normative epistemology

Concluding remarks