Is life as we know it a God-given thing or merely the product of chance? The argument over the nature of life raged through the twentieth century, with anti-religious scientists insisting that the very idea of the existence of the soul is no more than unnecessary religious mysticism, a smokescreen that clouds the real issues. To other people the idea that ‘life’ is something more than a chance combination of chemicals is both true and essential to the maintenance of a civilised society. Controversy rages over the nature of life. Biotechnology – the technology of life – is a flashpoint in this tense debate, linked as it is to issues over abortion, natural foods and to the idea of scientists playing God. The discovery of the structure of DNA, which has only raised the temperature of this debate, has led to new technologies of diagnosis and manipulation. Sometimes the debate is framed in terms of tight scientific argument, while at other times the so-called ‘yuk’ factor makes us wonder about the ‘naturalness’ of transferring genes between species, or using cells from fertilised eggs to grow replacement organs.