On the view of instincts having been slowly acquired through natural selection, we need not marvel at some instincts being not perfect and liable to mistakes, and at many instincts causing other animals to suffer.
Instintuak hautespen naturalaz astiro hartzen direla dioen teoriaren arabera, ez gaitu harritu behar zenbait instintu hobagarriak eta errakuntza-arriskua dutenak izateak, eta instintu askok beste animalia batzuei sufriarazteak.