I'm gradually managing to cram my mind more and more full of things. I've got this beautiful mind and it's going to die, and it'll all be gone. And then I say, not in my case. Every idea I've ever had I've written down, and it's all there on paper. And I won't be gone; it'll be there.

I do not use airplanes. They strike me as unsporting. You can have an automobile accident-and survive. You can be on a sinking ship-and survive. You can be in an earthquake, fire, volcanic eruption, tornado, what you will-and survive. But if your plane crashes, you do not survive. And I say the heck with it.

[A]ll knowledge is one. When a light brightens and illuminates a corner of a room, it adds to the general illumination of the entire room. Over and over again, scientific discoveries have provided answers to problems that had no apparent connection with the phenomena that gave rise to the discovery.

A scientist is as weak and human as any man, but the pursuit of science may ennoble him even against his will.

If I had felt then as I feel now, or as I felt a few years after I had married her, nothing could possibly have persuaded me to marry a woman who smoked. Dates, yes. Sexual adventures, yes. But to pin myself permanently inside closed quarters with a smoker? Never. Never. Never. Beauty wouldn't count, sweetness wouldn't count, suitability in every other respect wouldn't count.

A good question is, of course, the key by which infinite answers can be educed.

We're forever teetering on the brink of the unknowable, and trying to understand what can't be understood.