They agreed that humans shared a common ancestor with apes, but questioned whether any purely materialistic mechanism could account for all the differences between humans and apes, especially some aspects of the human mind.
Estaban de acordo con que os humanos compartían un antepasado común cos simios, pero cuestionaban que calquera mecanismo puramente materialista podería explicar todas as diferenzas entre os humanos e os simios, especialmente algúns aspectos da mente humana.