 In his First Letter, Autrecourt argues that Bernard’s views lead to an extreme form of skepticism. As he interprets the view, it would follow that intuitive cognitions cannot guarantee their own certitude: sensory illusions and the possibility of a deceptive God preclude this. But he goes further. As he explains, “you must say that you are not certain of your own acts, for example, that you are seeing or hearing”. Furthermore, “you are not certain whether anything appears to you at all” (First Letter 11). In short, one cannot be certain about any aspect of the external world, including even its very existence. And as he goes on to say, the existence of the past is equally uncertain, as is the very existence of one’s own mind.