The retreat of tuberculosis 1850–1950

stated that he brought the test case on behalf of general practitioners who were caught between the uncertainty of the law and pressure from patients. This suggests that public pressure had a role to play in medico-legal developments which cannot be viewed entirely in a vacuum. While Keown is concerned to trace the legal interpretation of biological facts, Norman Ford, a Catholic philosopher, seeks to make a moral judgement on the basis of embryological development. He brings Aristotelian philosophy to bear on scientific knowledge in order to determine when the human individual begins. In doing so Ford examines the historical significance of Aristotle's theory of human reproduction and then looks closely at the criteria for being a human individual. He argues against those who suggest that the human individual begins at fertilization. To substantiate his claims Ford guides the uninitiated reader through the complexities of embryological development to determine at what stage an ontological human begins. The complex embryology is made clear by useful diagrams and illustrations. Ford suggests that it is not possible to speak of an ontological human being as long as it is still possible for twins to develop. He concludes, therefore, that it is at the primitive streak stage (fourteen to fifteen days after fertilization) that is the crucial moment which differentiates between a potential and actual human individual. Ford's moral interpretation of the biological facts lends support to the conclusion of the Warnock Committee that experimentation on human embryos should stop at the fourteen-day stage. However, he does not go far beyond his carefully-drawn argument to look at its wider implications.