In the course of writing up our paper on “immoral promises,” we searched for and read the essay “Wicked Promises” by J.E.J. Altham, and in the process of obtaining Altham’s essay, we stumbled upon a short paper by Ian Hacking titled “Rules, scepticism, proof, Wittgenstein.” (Both essays appear in the book Exercises in Analysis, edited by Prof. Hacking. By the way, neither essay is available online. We actually had to go to a library and hunt for a physical copy of this obscure book!) Professor Hacking discusses the problem of indeterminate rules in his essay, a problem that is central to our field (law). To illustrate this problem, Hacking presents the following example of an indeterminate rule from the world of chess–a game may be drawn if the same position on the board occurs thrice–and then asks, what happens if the same position occurs thrice, but with black’s rooks interchanged? In the words of Hacking, two interpretations are possible: “One party says that the game is not drawn, because two positions in the course of the game are identical only if numerically identical pieces are on the same squares. *** The other party says that the game is drawn, because chess is a matter of structure on the board, not the history of the game. One rook is as good as another.” So, how should we decide which interpretation is the correct one?

Glinski’s hexagonal chess.