“ What ‘right’ to life has a man who must die if he is to save his children? If he chooses to save his own life, does he do so as a matter of ‘right’? If two men are starving and cannibalism is the only alternative to death, which man’s right is ‘unalienable’? And is it ‘right’? As to liberty, the heroes who signed the great document pledged themselves to buy liberty with their lives. ”
 Robert A. Heinlein, Starship Troopers (1959). copy citation