Abstract

This study evaluates the ontological and ethical premises and presuppositions of three abortion theorists: Germain Grisez, Eike-Henner W. Kluge, and Michael Tooley. ;Grisez's argument that human embryos and fetuses are moral persons because moral rights are derived from moral value, and the full moral value of human adults who are moral persons is implicit in the living genetic mechanism of all human beings, is criticized on the basis of the tension in Aristotle's doctrine between the notion of essence as an internal causitive principle, and as a set of observable qualities considered to be definitive of the nature of a living thing. However, David Wiggins' use of the semantical theory of natural kind terms of Hilary Putnam is suggested as a possible resolution. ;Kluge's argument that rational beings are moral persons because rational awareness has an absolute and intrinsic value, and that mature fetuses are moral persons because their neurological systems have become sufficiently complex to provide the present capability for rational awareness is criticized because he fails to show that mature fetuses do have such a present capability, and because his discussion of the relationship of potential being to actual being of living things wrongly presupposes that human gestation is analogous to the making of an artifact. ;Tooley's contrary argument that the right to life is not derivable from moral value but must, itself, be something violable, and that there is a conceptual connection between its violation and one's desire to continue to live, excludes fetuses and neonates because they lack the mental capability to desire to continue to live. Tooley's analysis is criticized as incomplete, and his argument as presupposing the existence of an essentially mentalistic self. ;The final chapter is a synthesis which considers the ontology of the development of personality or self, including the theories of Descartes, Locke and Wiggins. The conclusion is reached that theories which claim that a moral person "comes to be" as a fundamentally different kind of being at some point after conception, due to either morphological changes or the development of personality or self, entail dual principles of identity and, hence, are in danger of unintelligibility