We can characterise thought in two different ways. Which is preferred can have implications for important issues about reasoning and the norms that govern cognition. The first, which owes much to the picture of the mind encountered in Descartes' Meditations, observes that paradigmatic examples of thoughts and inferences are events and processes whose special characteristics stem from their being ‘mental’ occurrences. For example they are conscious or, if unconscious, they stand in some special relation to thought processes that are conscious. They typically involve attitudes towards contents or propositions. In general, thoughts have a distinctive onto-logical status and this status depends upon their being mental and typically conscious. The second emphasises that thought is a kind of activity with a definite function. It involves the use of intelligence to solve problems, answer questions, make plans and so on. Thought should be studied as a kind of goal-directed activity. Those interested in the norms that govern thought should attend to the role of responsible disciplined reflection in carrying out this activity.