 According to Wright’s (2011) characterisation, a presupposition of a cognitive project is any condition such that doubting it before carrying out the project would rationally commit one to doubting the significance or competence of the project irrespective of its outcome. For a wide class of cognitive projects examples of these presuppositions include: normal and proper functioning of the relevant cognitive faculties, the reliability of utilised instruments, the obtaining of the circumstances congenial to the proposed method of investigation, the soundness of relevant principles of inference utilised in developing and collating one’s results, and so on. 