Shea went home after a weary day of asking questions of neurotics, and had a good dinner. He put on the almost-new riding clothes and strapped over his polo coat a shoulder pack to hold his kit. He put on the hat with the green feather, and sat down at his desk. There, on sheets of paper spread before him, were the logical equations, with their little horse-shoes, upside-down T’s, and identity signs.

His scalp prickled a trifle as he gazed at them. But what the hell! Stand by for adventure and romance! He bent over, giving his whole attention to the formulas, trying not to focus on one spot, but to apprehend the whole:

«If P equals not-Q, Q implies not-F, which is equivalent to saying either P or Q or neither, but not both. But if not-P is not implied by not-Q, the counter-implicative form of the proposition —»

There was nothing but six sheets of paper. Just that, lying in two neat rows of three sheets, with perhaps half an inch between them. There should he strips of table showing between them. But there was nothing — nothing.

«The full argument thus consists in an epicheirematic syllogism in Barbara, the major premise of which is not the conclusion of an enthymeme, though the minor premise of which may or may not be the conclusion of a non-Aristotelian sorites —»

The papers were still there, but overlaying the picture of those six white rectangles was a whirl of faint spots of colour. All the colours of the spectrum were represented, he noted with the back of his mind, but there was a strong tendency toward violet. Round and round they went — round — and round — «If either F or Q is true or (Q or R) is true then either Q is true or (P or R) is false —»

Round and round — He could hear nothing at all. He had no sense of heat or cold, or of the pressure of the chair seat against him. There was nothing but millions of whirling spots of colour.