Power.

"It is true that if we ever did stop to think about the cosmos we might find it uncomfortable. The sun may grow cold or blow up; the earth may lose its atmosphere and become uninhabitable. Life is a brief, small, and transitory phenomenon in an obscure corner, not at all the sort of thing that one would make a fuss about if one were not personally concerned. But it is monkish and futile- so scientific man will say- to dwell on such cold and unpractical thoughts. Let us get on with the job of fertilizing the desert, melting Arctic ice, and killing each other with perpetually improving technique. Some of our activities will do good, some harm, but all alike will show our power. And so, in this godless universe we shall become gods."

Lord Bertrand Russell
(I.S.S.p15)