Once acclimatized to space living, it is unlikely that man will stop until he has roamed over and colonized most of the sidereal universe, or that even this will be the end. Man will not ultimately be content to be parasitic on the stars but will invade them and organize them for his own purposes.

The World, the Flesh and the Devil: An Enquiry into the Future of the - Three Enemies of the Rational Soul, Chapter II (pp. 27-28)