The term "reasonable creature" echoes the language of an influential strand Catholic doctrine on the nature of the soul and the Beginning of human personhood which generally adopted Aristotle in holding that it is the "rational soul" that infuses the fetus with "human beingness". There was disagreement as to whether this occurred at the moment of conception, or at the moment of quickening, as Aristotle had held. As for "rerum natura", William Staunford had explained "the thing killed must be in part of the world of physical beings (in rerum