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.
Ernest SosaIn 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.
Ernest SosaIf the agent aims to make the attempt if and only if it would be apt, then a distinctive element of risk assessment becomes relevant: How probably would the agent succeed in attempting that fuller end?
Ernest SosaGiven its more substantial aim, a judgment is apt only if its constitutive alethic affirmation is not only apt but aptly apt. The subject must attain aptly not only the truth of his affirmation but also its aptness. And that in turn requires not only the proper operation of one's perception, memory, inference, etc., but also that one deploy such competences through competent epistemic risk assessment.
Ernest Sosa