The emergent new science of synthetic biology is challenging entrenched distinctions between, amongst others, life and non-life, the natural and the artificial, the evolved and the designed, and even the material and the informational. Whenever such culturally sanctioned boundaries are breached, researchers are inevitably accused of playing God or treading in Frankenstein’s footsteps. Bioethicists, theologians and editors of scientific journals feel obliged to provide an authoritative answer to the ambiguous question of the ‘meaning’ of life, both as a scientific definition (...) and as an explication with wider existential connotations. This article analyses the arguments mooted in the emerging societal debates on synthetic biology and the way its practitioners respond to criticism, mostly by assuming a defiant posture or professing humility. It explores the relationship between the ‘playing God’ theme and the Frankenstein motif and examines the doctrinal status of the ‘playing God’ argument. One particularly interesting finding is that liberal theologians generally deny the religious character of the ‘playing God’ argument—a response which fits in with the curious fact that this argument is used mainly by secular organizations. Synthetic biology, it is therefore maintained, does not offend so much the God of the Bible as a deified Nature. While syntheses of artificial life forms cause some vague uneasiness that life may lose its special meaning, most concerns turn out to be narrowly anthropocentric. As long as synthetic biology creates only new microbial life and does not directly affect human life, it will in all likelihood be considered acceptable. (shrink)