  In his Letter to Bernard, Autrecourt takes on Bernard of Arezzo, who had argued that the intellect is neither certain of the existence of those things of which it has a clear intuitive cognition, nor of its own acts. Autrecourt reveals the full implications of this position by pointing out to Bernard that “you are not certain of those things which are outside of you. And so you do not know if you are in the sky or on earth, in fire or in water...Similarly, you do not know what things exist in your immediate surroundings, such as whether you have a head, a beard, hair, and the like.” He concludes that Bernard’s stance is even worse than that of “the Academics,” that is, the ancient Skeptics.