3 Augustine, we might say, does describe a system of communication, only not everything that we call 'language' is this system. And one has to say this in many cases where the question arises "Is this an appropriate description or not?" The answer is: "Yes, it is appropriate, but only for this narrowly circumscribed region, not for the whole of what you were claiming to describe."

It is as if someone were to say: "A game consists in moving objects about on a surface according to certain rules..."--- and we replied: You seem to be thinking of board games, but there are others. You can make your definition correct by expressly restricting it to (only) those games.

ELUCIDATION

  1. The last word would be better as 'activities'.
  2. 'Game' is his key  illustration, in 66, of a word which does not refer to any clearly bounded region of activities in the world. It therefore has no essential meaning, though it nonetheless does a good job for us in ordinary use.
  3. He is criticising his intellectual tendency in his Tractatus to oversimplification and inappropriate abstraction. This is indeed a typical danger for the intellectual. Abstraction and simplification are very attractive tools for those that can master them, and achieve very powerful results in some areas, such as mathematics and physics. This does not imply that they are constructive tools for use in all areas. In some areas, far from enabling us to find the truth, they will obscure it.
  4. It was the criticism of his friends Ramsey and Sraffa which finally made him see that language served many more human purposes than the one he had singled out in the Tractatus. Apparently Sraffa asked him how this - at which point he shrugged - fitted into his Picture Theory of language.
  5. There is no harm in restricting the meaning/use of a word for some particular purpose - giving it, say, a special technical meaning (such as 'weight' in Physics) - as long as we are quite clear that this is what we have done. But we shouldn't pretend that we have thus unpacked or analysed the real, essential, meaning of the word; we have merely defined a new, more precise, meaning/use for it, for our convenience.