We planned this book as a Festschrift for Smitty Stevens because we thought he might be retiring around 1974, although we knew very well that only death or deep illness would stop Smitty from doing science. Death came suddenly, unexpectedly - after a full day of skiing at Vail, Colorado on the annual trip with wife Didi to the Winter Conference on Brain Research. Smitty liked winter conferences near ski resorts and often tried to get us other psychophysicists to organize one. Every person is unique. Smitty would have said it's mainly because each of us has so many genes that two combinations just alike would be well-nigh impossible. But most of us strive in many ways to be like others, and to abide by the rms (some smaller number try even harder to be unlike other people); as a result many persons seem to lose their uniqueness, their individuality. Not Smitty. He tried neither to be like others r to be different. He took himself as he found himself, and ascribed peculiarities, strengths, and weaknesses to his pioneering Utah forebears, in whom he took much pride. His was the true and right nconformity. He approached each task, each problem, ready to grapple with the facts and set them into meaningful order. And if the answer he came up with was different from everyone else's, well that was too bad.