a thing without knowing what it is. That is why a great deal of contemporary thought is, strictly speaking, thought about nothing—all the apparatus of thought busily working in a vacuum. The other objection is this: let us go back to the toolshed. I might have discounted what I saw when looking along the beam (i.e., the leaves moving and the sun) on the ground that it was ‘really only a strip of dusty light in a dark shed’. That is, I might have set up as ‘true’ my ‘side vision’ of the beam. But