 Finally, we may turn to the work of Donald Davidson, who like Putnam bases his transcendental claim on a form of externalism, which links the content of our mental states to how we relate to our environment; but in his case, this idea is directed against skepticism concerning other minds. Thus, while the skeptic holds that the existence of such minds is doubtful, Davidson argues that it would not be possible for a creature like me to have thoughts unless I lived in a world with other creatures who also had thoughts, so the truth of the latter can be deduced from the fact that I am indeed capable of thinking: ‘What are the conditions necessary for the existence of thought, and so in particular for the existence of people with thoughts? I believe there could not be thoughts in one mind if there were no other thoughtful creatures with which the first mind shared a natural world’ (Davidson 1989: 193). Davidson’s transcendental argument is based on his account of what it takes for a thought to have content, for which he argues that a process of ‘triangulation’ must occur, whereby the content of the thought someone is having is ‘fixed’ by the way in which someone else correlates the responses he makes to something in the world. Thus, Davidson argues, if there were no other people, the content of our thoughts would be totally indeterminate, and we would in effect have no thoughts at all; from the self-evident falsity of the latter, he therefore deduces the falsity of the former (cf. Davidson 1991: 159–60). Davidson therefore argues that the mistake the skeptic makes, in common with the Cartesian heritage of which he is part, is in the assumption that it is possible to be a lone thinker: Davidson’s transcendental argument is designed to show that this is not in fact the case, given the constraints on what it takes to have thoughts with content, so that the existence of a single thinking subject entails the existence of others.