I have lost my sense of a universe. They say this is the richest era of human existence; but I think a man can be richer in knowing every atom of a s… - Robert Silverberg

A man who lies to himself is the worst liar of all.

I have come to prefer something looser, a rough sort of definition which says simply that science fiction attempts to portray that which does not exist, a speculative reality, but endeavors to explore the consequences of such a speculation in a rigorous, systematic, and scientifically plausible way.

The process of changing your mind is a tricky one. You start at Position A, which you hold with stern stubbornness, resolving never to give it up. Then you start to question your original resolution. Is it wise to be so stubborn? Perhaps you should consider alternate ideas. You revise your original inflexibility a little, abandoning Position A and adopting Position B, which is very much like it in most ways, with only a few ifs and maybes added. Then, by a gradual series of compromises, private deals, and shifts of purpose, you slide spinelessly through the alphabet until you arrive at Position Z, the total opposite of your original point of view.