Raymond Smullian and Retrograde Analysis Chess Problems: A Philosophical Perspective

Abstract

The article deals with the logico-epistemological and philosophical aspects of the creative work of Raymond Smullyan as a chess composer. He is well known as the author of many problems from the field of the so-called retroanalysis, which is an excellent field for constructing not only puzzles ideologically close to the classical problems of knights and knave, but also more serious, theoretically loaded cases. In the paper, three examples of such modeling are analyzed in detail. In particular, it turns out that the intuitionistic principle of constructive proof (also associated with the Smullyan's "paradox of inconsistency") on the chess material and the dispute between the nominalists and realists. Of particular interest is the "problem of the returned rook", where the question of the criteria for the identity of objects is raised with the utmost urgency in the language of retroanalysis (here, too, the connection with the well-known "Theseus's paradox" is evident), on the notion of essential and non-essential changes. It should be noted that Smullyan himself is clearly incomplete, his detailed specification is given, as well as an assessment from the point of view of not only the letter, but also the spirit of chess rules (which the author claims to reconstruct in this aspect). Particular attention is paid to the problem of accuracy, unambiguity and completeness of the chess rule of castling (as well as the definition of the term "move"), which plays a major role in this case. This case is also regarded as an excellent tool for training argumentative skills. Thus, retroanalysis and philosophy enrich each other, allow us to look at them from an unexpected side. The article underscores the undoubted importance of this relationship for the popularization of science in particular and intellectual culture in general.