An oil painting of Ludwig Wittgenstein by Mike Newton.

Can language present our inner mental states? No, said Ludwig Wittgenstein (b. 1889). These states are not expressible in words.

If I am in pain, I can only sense it; I cannot know it—that doesn’t make any sense. For what does it mean to know I’m in pain?! I’m in pain; saying so adds nothing since I cannot be in pain and not know it—the knowledge-claim simply collapses to my being in pain. There can be no private rule-following.

But perhaps there is scope for public language between people? Indeed, another person may deduce my pain correctly from the words or signs I use—even primitive ones, such as my grimaces and my whines. Then again, perhaps I am faking it. What’s the solution?

Building on Wittgenstein’s work, Saul Kripke (b. 1940)—Kripkenstein!—writes that a community follows linguistic rules which give ‘signs’ their meanings. What does 2+2 equal? Well, 4 because ‘+’ means ‘plus’. While ‘+’ could be ‘quus’, denoting a different rule, the community doesn’t follow the ‘quus’ rule and I can corroborate my answer with theirs.

However, Wittgenstein said such thinking is exposed to the ‘rule-following paradox’. The answer to what ‘+’ means is not fixed: multiple rules are available and establishing a specific one is not guaranteed. Quite possibly, the community interprets ‘+’ as something else or misremembers the original meaning, creating conflicts in rules. So Kripke merely postpones the problem with his pragmatic, not analytic, proposal.

To quote Wittgenstein in Philosophical Investigations:

‘A rule stands there like a signpost.—Does the signpost leave no doubt about the way I have to go? Does it show which direction I am to take when I have passed it, whether along the road or the footpath or cross-country? But where does it say which way I am to follow it; whether in the direction of its finger or (for example) in the opposite one?—And if there were not a single signpost, but a sequence of signposts or chalk marks on the ground—is there only one way of interpreting them?—So I can say that the signpost does after all leave room for doubt.’

Meaning is still possible, says Wittgenstein. It is the external relations of a community’s public language game (the context) that introduces conflicts in rules; but there are inner relations in each of us that channel meaning. However, I must ‘follow the rule blindly’—for example, like babies who express pain by crying and like adults who intuitively respond in similar ways to training. Restricting meaning to these dissolves the paradox.

But how many of these inner relations are followed blindly and how many are empirically learned? For while I think reading left to right is intuitive, many people do not.