The Chief Medical Officer of Health of the United Kingdom has recommended that the 1990 Human Fertilisation and Embryology Act should be amended to allow cloning in humans for research purposes only. He also recommended that: “The transfer of an embryo created by cell nuclear replacement into the uterus of a woman (so called ‘reproductive cloning’) should remain a criminal offence” (recommendation 7, Ref. 1). This recommendation implies that nuclear replacement and cloning are the same. They are not. Nuclear transfer (...) constitutes reproductive cloning only when the individual created is genetically identical to the nuclear donor. In this paper, we describe a possible future use of nuclear transfer for the treatment of infertile individuals. The treatment yields an individual that receives approximately equal genetic contributions from each parent. We use this example to illustrate how semantic confusion might lead to plausibly moral and justifiable treatments being legally banned. In doing so, we hope to encourage a more accurate and informed use of language in science, law and politics, so that legislation is properly informed by science and achieves what it intends. BioEssays 23:359–364, 2001. © 2001 John Wiley & Sons, Inc. (shrink)