All evil is good become cancerous.

Well, sir to say that when the impossible has been eliminated, whatever remains, however improbable, is the truth, is to make the assumption, usually justified, that everything that is to be considered has indeed been considered. Let us suppose we have considered ten factors. Nine are clearly impossible. Is the tenth, however improbable, therefore true? What if there were an eleventh factor, and a twelfth, & a thirteenth...

All roads lead to Trantor, and that is where all stars end.

It is not so much that I have confidence in scientists being right, but that I have so much in nonscientists being wrong.

Past glories are poor feeding.

It was a long time since he'd done any actual clinical work, and obviously his sojourn among the academics at Saro University had attenuated the professional detachment that allows members of the healing arts to confront the ill without being overwhelmed by compassion and sorrow. He was surprised at that, how tenderhearted he seemed to have become, how thin-skinned.