The nature of intentions is a perpetual locus of interest for investigators of the human mind. Both occidental and oriental philosophical traditions treat intentions as the root of behavior; and many possible classifications have been offered in order to try to systematize the different types of intention. Moreover, recognition of intentions in others appears to be central to child development, and necessary for becoming a competent member of the society. Recent work in the social neurosciences has focused, in particular, on social intentions, which may underpin the human predisposition toward joint, collaborative behavior. Communicative intentions are particularly central, yet have a puzzling recursive form.