Crathorn thus had to emend Ockham’s theory of evident knowledge, because intuitive cognition is no more the guarantee of any certitude regarding the existence of extramental things. In addition, the cognition of the terms of a proposition — even a per se nota proposition — is not sufficient, according to Crathorn, to ensure the causal mechanism that leads to evidence and certitude. Indeed, as we shall see below, Crathorn refuses to treat the species or cognitions as linguistic elements of though