Arguably, if you view a real barn in bright sunlight and close by, while fully alert and otherwise in good shape, then you do know whether or not you see a barn. You have "animal" knowledge, says my virtue theory, through the first-order aptness of your judgment.

In order to qualify as a judgment, an affirmation must aim at getting it right aptly, through competence, and not just through a lucky guess.

When I accept someone's testimony, I am thus only a small part of the full seat of epistemic competence, which might include many others in a long chain. My own contribution might then be slight, just through the perceptual and linguistic competence involved in knowing what someone is saying or writing, etc.

I am mainly concerned with unqualified knowledge, by contrast with the varieties of expert knowledge: scientific knowledge of various sorts, legal knowledge, medically expert knowledge, and so on.

In my view (animal) knowledge is apt belief, where not only the belief (its existence and content) but also its correctness is creditable to the subject's competence.

There's not much to be done about the impossibility. One must instead get rid of the desire.

The risk pertinent to a particular attempt (and to its evaluation as an attempt of its sort) is the risk that the agent will fail to attain the end constitutive of that attempt. This risk of failure is coordinate with how likely or unlikely it may be that the agent will then succeed.