La gratitud es mejor y más eficaz cuando no se evapora en frases vacías. - Isaac Asimov

Connotations and associations; the subtle effect, not of dictionary meaning, but of years of usage; the nature of the sentences and conditions and events in which one has experienced the use of one word as compared with that of the other.

If you were to insist I was a robot, you might not consider me capable of love in some mystic human sense, but you would not be able to distinguish my reactions from that which you would call love — so what difference would it make?

I know this much: species evolve only to meet the pressures of new environments. In a stable environment, a species may remain unchanged for millions of Centuries. Primitive man evolved rapidly because his environment was a harsh and changing one. Once, however, mankind learned to create his own environment, he created a pleasant and stable one, so he just naturally stopped evolving.