There’s so much to love in this note Asimov sent to another friend on March 22, 1966:

Sagan has read half through my book on the universe and has caught one fundamental error so far. In my rendering of Eddington’s theories on stellar structure, I talked of radiation pressure. Apparently, I didn’t have to. Fortunately, it just means correcting a sentence here and there.

But that’s what I need Sagan for. Anything he doesn’t catch isn’t there to be caught. If only he were a little faster about it. I said to him I realized he was awfully busy, too, but then I added with my particular brand of ingenuousness, “But then, what is your work compared to mine?”

And he said, “You say it in such a way that I can take it as a joke. But you really mean it, don’t you?”

So I made the best of it. I said, “Yes, I do.”

A very smart fellow, that Sagan.

Read more: http://brainpickings.org/index.php/2013/07/22/isaac-asimov-carl-sagan-letters/