   Troubled by the statement from Hume, Reid constructs a reductio argument against Hume's theory of thought that plays upon the implications just noted. Reid presents this argument about the intentionality of thought through an analogy about the meaning of language, specifically, about someone who is blind to the meaning of the language in a book. Suppose I see unfamiliar ink marks on paper. I neither know what they mean nor even that they are meaningful to anyone. The meanings of these words are not intrinsic to the representations of the words, whether those representations are on paper or are sound waves, just like the intentional content of ideas is not intrinsic to the ideas themselves. Reid writes: