Perception,discrimination, and knowledge

In perception, perceivers discriminate. They distinguish or single out the objects and property instances that they see. One might hope this discriminatory nature of perception could help explain how perceptual evidence can be sufficient for knowledge, even granting some form of a relevant alternatives condition on knowledge. Indeed, there are examples of such thinking in recent epistemology literature. But I argue that discriminating actual percepts from actual surrounds is importantly different than discriminating actual states of affairs from merely possible states of affairs. A tension remains between optimism about immediate perceptual knowledge and plausible relevant alternatives or safety conditions on knowledge in general.