In arriving at the relevant theory about the specifics of our faculty of vision we will presumably use our eyes to gather relevant data. Based on such data we come to know about the optic nerve, the structure of our eyes, the rods and cones, etc., so as to explain how it is that vision gives us reliable access to the shapes and colors of objects around us. In reliably arriving at that theory we thus exercise the very faculty whose reliability is explained by the theory. There is no vice in this sort of circularity.

The success of an archery shot may bring food to the hunter's starving family, or may constitute a horrible murder. But these outcomes are irrelevant to the assessment of that shot as a hunter-archery shot, as an attempt to hit prey without running excessive risk of failure.

There is no need for the scientist to go into whether an observation was made, nor into the who, what, when, or where. The data on which scientific theorizing is based are rather the propositional contents of the instrument readings recorded, or the facts detected thereby.

Through our perceptual systems, we represent our surroundings, aiming to do so accurately, where the aiming is functional or teleological, rather than intentional. And the same goes for our functional beliefs. Through our judgments, however, we do intentionally, even consciously, attempt to get it right.

Any defense of common sense must allow that it is revisable.

In competitive archery, risk assessment has minimal bearing on quality of performance, since the archer has so little choice over shot selection. By contrast, in a hunt, shots vary in quality according to how well selected they may be.

Descartes's epistemology is a special case of Aristotle's virtue ethics.