  Autrecourt defends the thesis that what appears, is, and that what appears true, is true. He finds this view more plausible than its opposite, viz., that the intellect cannot possess certitude. Autrecourt does not have a meta-theory in which he defends his model of certain knowledge against alternative theories. His appeal that his theory is the more probable one, however, saves him from charges of dogmatism. His concept of appearance plays a key role in his doctrine of certain knowledge. It is used in a phenomenological sense, to describe perceptual experiences. According to Autrecourt, the intellect is certain of everything that is evident to it in the final analysis. This is the case for everything that appears in a proper sense (apparet proprie), i.e., that appears clearly in an act of the external senses (in actu sensuum exteriorum). He identifies appearances with the objects of immediate sensory experience, which are considered evident. In this way, he implies that sense perception is a reliable source of truth, i.e., that the apparent properties of an object are its actual properties.