The word ?consciousness? is notoriously ambiguous. This is mainly because it is not a term of art, but a mundane word we all use quite frequently, for different purposes and in different everyday contexts. In this paper, I discuss consciousness in one specific sense of the word. To avoid the ambiguities, I introduce a term of art ? intransitive self-consciousness ? and suggest that this form of self-consciousness is an essential component of the folk notion of consciousness. I then argue (...) for a specific account of consciousness as intransitive self-consciousness. According to this account, a mental state is conscious iff it represents its own occurrence. The argument is a ?modernizing? modification of an older argument due to Aristotle and Brentano. (shrink)