Matti Häyry’s new book Rationality and the Genetic Challenge discusses the ethics of human genetic modification and the bioethical rationalities that inform the different ethical conclusions authors have advanced. It is aimed at correcting the belief that “only one rationality exists or one morality exists; that those that disagree [with them] are unreasonable or evil.” Häyry argues that there are multiple rationalities, and that even though ethical issues may have solutions within individual rationalities, disagreements that have their root in separate (...) rational approaches cannot be universally solved by intellectual arguments. In debates about the ethics of using new biotechnologies to genetically modify human beings, the normal state is one of fundamental disagreement over almost all of the anticipated uses to which the technology could be put. Häyry’s point is that such a state of affairs is not necessarily due to a lack of reason because there are many, equally valid, ways of being reasonable. (shrink)