Thesis Sellars was right that raw experience can cause a belief but never justify one
Its coordinates: 2.2 Sources of Knowledge · 2.2.2 Reason and Intuition
Where it stands
The more I read about visual perception, the more I think Wilfrid Sellars got something exactly right in "Empiricism and the Philosophy of Mind" (1956).
The foundationalist wants a floor: beliefs justified without leaning on other beliefs. The obvious candidate is experience itself, the bare redness before any interpretation. Sellars's dilemma is that for something to justify a belief, it has to stand in logical relations to it. It has to have content that can be correct or incorrect. But anything with that kind of content is already conceptual, already an interpretation, and so it can itself be questioned. A raw sensation without content can make you believe something, the way a loud noise makes you jump. It cannot be your reason.
The perception science pushes me further in this direction. On predictive processing accounts, there is no stage at which an uninterpreted input arrives and is then interpreted. Expectation shapes the signal from very early on. I do not think neuroscience settles a philosophical question, and I am aware that "the brain does X" is not "the given is a myth". But it makes the picture of a pure, pre-conceptual floor look like an artefact of armchair introspection.
So my thesis: experience causes beliefs; only other contentful states justify them. Foundationalism needs a floor that does both jobs, and nothing does.
I would particularly like objections from people who know the Buddhist epistemologists, since Dignāga and Dharmakīrti held that perception is free of conceptual construction and still counted it a means of knowledge. If they had a way to make that work, I want to hear it.