The beginning of human life is seen differently by different individuals, groups, cultures, and religions. Embryonic and fetal life are a continuum, within which are time sequences and points--birth of a newborn, viability, neuromaturation, implantation, and conception--that may be declared as the beginning of human life. For each of these there are ethical and legal implications and considerations. Abortion laws reflect the interests of a given society at a given time. Although we have witnessed a change in the United States from virtual denial of the right to abortion to acceptance for certain reasons, abortion laws remain ambiguous. With the recent introduction of the antiprogesterones, it is conceivable that we will soon witness yet another procreation revolution with consequent increased controversy. Fundamental to productive debate and reconciliation between minority and majority groups is an understanding of the ill-defined concept of "the beginning of human life."