The Gap in the Curtain by John Buchan

I find it almost impossible to give the gist of the conversation which filled the next forenoon. We sat in wicker chairs on the flags of the Dutch garden in a grilling sun, for heat seemed to be the one physical comfort for which the Professor craved. I shall always associate the glare of a June sky with a frantic effort on my part to grasp the ultimate imponderables of human thought.

The Professor was merciful to my weakness. He had a great writing- pad on his knee, and would fain have illustrated his argument with diagrams, but he desisted when he found that they meant little to me and really impeded his exposition. Most scientists use a kind of shorthand -- formulas and equations which have as exact a meaning for them as an ordinary noun has for the ordinary man. But there was no chance for this shorthand with me. He had to begin from the very beginning, taking nothing for granted. I realised his difficulty. It was as if I had had to argue an intricate case, not before a learned judge, but before an intelligent ignoramus, to whom each technical legal term had to be laboriously explained.