Human civilization means we have got so many animal propensities, and if we can control them, that is advancement of human civilization. Just try to understand. Not that "Because I have got this tendency, let me increase it without any restriction." That is not human civilization. Human civilization... That is the distinction between animal and human being. Tapasa brahmacaryena samena [SB 6.1.13].
Lecture on Srimad-Bhagavatam 1.16.21, Hawaii, 17 January, 1974