Saul Kripke

Saul Kripke turned a few remarks of Wittgenstein's into one of the most debated arguments in modern philosophy. Already famous for Naming and Necessity, his lectures of 1970 on reference and necessity, Kripke published Wittgenstein on Rules and Private Language in 1982. Its version of Wittgenstein is so distinctive that philosophers nicknamed it "Kripkenstein".

The paradox he found

Kripke started from a remark in the Philosophical Investigations.

Unser Paradox war dies: eine Regel könnte keine Handlungsweise bestimmen, da jede Handlungsweise mit der Regel in Übereinstimmung zu bringen sei.

Our paradox was this: a rule could not determine any course of action, because every course of action can be made to accord with the rule.

Philosophical Investigations §201

Suppose you have never added numbers larger than 57, and someone asks you for 68 + 57. You answer 125. But a sceptic asks: how do you know that in the past you meant addition by "plus", and not "quus", a function that gives the same answers as addition below 57 and gives 5 otherwise? Nothing in your past behaviour, and nothing in your mind, seems to settle it. Any finite history of use fits endlessly many rules.

His sceptical solution

Kripke's Wittgenstein accepts that there is no fact that makes it true that you meant plus. In place of truth conditions he offers assertibility conditions: we are entitled to say someone means addition when their answers agree with those of the community. Meaning becomes a matter of shared practice and mutual checking. One consequence: a person considered in isolation cannot be said to follow rules at all. That is why, for Kripke, the private language argument is already contained in the discussion of rule-following, before §243.

Where the disagreement lies

Kripke himself was careful. He presented the argument as Wittgenstein's argument as it struck him, not necessarily as Wittgenstein meant it, and he did not claim to endorse it. Many readers think it struck him wrongly. In the very same §201 Wittgenstein says the paradox rests on a misunderstanding, and that there is a way of grasping a rule which is not an interpretation but shows itself in what we call obeying the rule and going against it.

Gordon Baker and Peter Hacker and Colin McGinn (both 1984) argued that Wittgenstein dissolves the paradox instead of accepting it. John McDowell argued that the problem only arises if understanding is pictured as interpreting, and Stanley Cavell objected to Kripke's picture of a community enforcing its verdicts. The Internet Encyclopedia of Philosophy and the Stanford Encyclopedia set out these replies. Whether or not Kripkenstein is Wittgenstein, it forced everyone to read the rule-following remarks far more closely.