Embryonic life and human life

Abstract

A new human life comes into being not when there is mere cellular life in a human embryo, but when the newly developing body organs and systems begin to function as a whole, the author argues. This is symmetrical with the dealth of an existing human life, which occurs when its organs and systems have permanently ceased to function as a whole. Thus a new human life cannot begin until the development of a functioning brain which has begun to co-ordinate and organise the activities of the body as a whole.

KIE: Shea presents arguments for determining the beginning of human life as that time when fetal organs and systems begin to function as an organized whole, directed by the brain. She defines the zygote and embryo as transitional stages, periods of differentiation and multiplication at the cellular level. After an embryo reaches a certain degree of complexity, development can continue only if its parts begin to function together at a holistic level, laying the foundation for more advanced activities of synthesis and thought. Shea concludes with a brief discussion of the ethical implications that this definition of life has for in vitro fertilization (IVF), experimentation with "spare" IVF embryos, and abortion.