You know, it's such a beautiful day that I think I'll walk. - Isaac Asimov

I thought you could feel love for me. I don't say you loved me, but it seemed to me you could. I never had that and, although in ancient literature they talked of it, I didn't know what they meant any more than when men in those same books talked about 'honor' and killed each other for its sake.

"Didn't you study psychology under Alurin?"

Hardin answered, half in reverie: "Yes, I never completed my studies, though. I got tired of theory. I wanted to be a psychological engineer, but we lacked the facilities, so I did the next best thing — I went into politics. It's practically the same thing."

Un robot es una máquina computerizada que es capaz de realizar un tipo de tareas que son demasiado complejas para cualquier mente viviente aparte de la del hombre, y de unas características que una máquina no-computerizada no es capaz de realizar.