Ayer's denying of synthetic ostensive propositions

Question

Let us suppose that I assert the proposition ‘This is white’, and my words are taken to refer, not, as they normally would, to some material thing, but to a sense-content. Then what I am saying about this sense-content is that it is an element in the class of sense-contents which constitutes ‘white’ for me; or in other words that it is similar in colour to certain other sense-contents, namely those which I should call, or actually have called, white. And I think I am saying also that it corresponds in some fashion to the sense-contents which go to constitute ‘white’ for other people: so that if I discovered that I had an abnormal colour-sense, I should admit that the sense-content in question was not white. But even if we exclude all reference to other people, it is still possible to think of a situation which would lead me to suppose that my classification of a sense-content was mistaken. I might, for example, have discovered that whenever I sensed a sense-content of a certain quality, I made some distinctive overt bodily movement; and I might on one occasion be presented with a sense-content which I asserted to be of that quality, and then fail to make the bodily reaction which I had come to associate with it.

This is quote from Ayer's "Language, truth and logic", chapter 5.

Can someone give an example of the situation described in the end of the quote, the one about bodily reaction?

Answer 1

It seems Ayer is making a basic confusion. First:

Let us suppose that I assert the proposition ‘This is white’, and my words are taken to refer, not, as they normally would, to some material thing, but to a sense-content. Then what I am saying about this sense-content is that it is an element in the class of sense-contents which constitutes ‘white’ for me; or in other words that it is similar in colour to certain other sense-contents, namely those which I should call, or actually have called, white.

Ayer says his sentence, ‘This is white’, does not refer to any material thing, but refers instead to a sense-content, which presumably we would now call "whiteness". It is presumably the same thing as the quality we experience subjectively whenever we are looking as something which we see as white. What we also call the quale of white.

Yet, the sentence is not appropriate to this particular species of references. We use "this" to call someone else's attention to something which is visible at least for us. Our mind is not part of that. Nobody has access to our mind except ourselves. It is pointless to call someone else's attention on something which is inside our own mind.

so that if I discovered that I had an abnormal colour-sense, I should admit that the sense-content in question was not white.

This is absurd. It is as absurd as saying that on using the word "red" to mean the colour white, I am wrong not in using the wrong word but in mistaking the colour white for the colour red.

But even if we exclude all reference to other people, it is still possible to think of a situation which would lead me to suppose that my classification of a sense-content was mistaken. I might, for example, have discovered that whenever I sensed a sense-content of a certain quality, I made some distinctive overt bodily movement; and I might on one occasion be presented with a sense-content which I asserted to be of that quality, and then fail to make the bodily reaction which I had come to associate with it.

This seems wrong, too. Ayer claims to be talking again about what he called "sense-content", something presumably inside someone's mind, but then seems to shifts the reference to some bodily movement, something presumably outside the mind, and therefore part of the material world he just pretended not to be talking about.

Either Ayer didn't understand something, or failed to articulate properly his idea.