Your coverage of animal research (http://www.nature.com/animalresearch) focuses on well-worn themes from proponents, but does offer a way forward.

British biologist Peter Medawar predicted years ago that the use of animals in research would some day be completely replaced by more innovative methods (The Hope of Progress, Methuen; 1972). And Colin Blakemore, an ardent defender of animal research, has repeatedly stated that: “Everyone hopes that a time will come when no animal is used at all.” To translate these congruous perspectives into action, we need to develop the kind of proactive strategies that you call for.

The results of your poll (Nature 470, 452–453; 2011) indicate that some scientists might be ready to take this idea forward. Others are clearly not immune to the ethical tensions in animal research. Sadly, most feel that the polarized debate on animal research makes it difficult to express more nuanced views, presumably because they do not want to be perceived as giving ammunition to the extremists.

Medawar's vision to replace animal experimentation is a goal that is worthy of serious effort, for the sake of scientific innovation, ethical responsiveness and animal protection. We should not be deterred by either the scientific challenges or the actions of a handful of extremists.