Sir

Sahakian and Morein-Zamir's Commentary 'Professor's little helper' (Nature 450, 1157–1159; 2007) makes an important contribution to the neuroethics of enhancement, as much for what it doesn't say as for what it does.

Much of the debate over neurocognitive enhancement has been guided by the so-called 'wisdom of repugnance'. We are encouraged to focus on our gut reaction to perfectly healthy individuals drugging themselves (or worse, their healthy children) for the sake of satisfying oversized ambitions. This highlights issues such as the need to earn one's success and self-esteem, and respect for our natural limitations.

Shouldn't we attempt a more rational analysis of the different contexts, methods and motives for neurocognitive enhancement and their likely outcomes, including the likely impact on society and human values?

Sahakian and Morein-Zamir provide a cautious yet open-minded assessment of risks and benefits, without any obeisance to the wisdom of repugnance. They have done us a service in framing the issues in this way.