An ant is crawling on a patch of sand. As it crawls, it traces a line in the sand. By pure chance the line that it traces curves and recrosses itself in such a way that it ends up looking like a recognizable caricature of Winston Churchill. Has the ant traced a picture of Winston Churchill, a picture that depicts Churchill?

Most people would say, on a little reflection, that it has not. The ant, after all, has never seen Churchill, or even a picture of Churchill, and it had no intention of depicting Churchill. It simply traced a line (and even that was unintentional), a line that we can ‘see as’ a picture of Churchill.

We can express this by saying that the line is not ‘in itself’ a representation of anything rather than anything else. Similarity (of a certain very complicated sort) to the features of Winston Churchill is not sufficient to make something represent or refer to Churchill. Nor is it necessary: in our community the printed shape ‘Winston Churchill’, the spoken words ‘Winston Churchill’, and many other things are used to represent Churchill (though not pictorially), while not having the sort of similarity to Churchill that a picture – even a line drawing – has. If similarity is not necessary or sufficient to make something represent something else, how can anything be necessary or sufficient for this purpose? How on earth can one thing represent (or ‘stand for’, etc.) a different thing?