Page "Brute fact" Paragraph 2

That my computer is displaying a picture of a cat to me can be explained in terms of facts about the voltages in bits of metal in my computer ; in turn, these facts about voltages can be explained in terms of facts about the positions and velocities of subatomic particles.

Ultimately, some set of facts might be reached whose truth does not depend upon any set of more fundamental facts.

Such facts are brute or fundamental facts.