Sociologists, like economists, have never been very good at verifying the ‘models of man’ that they use. Both ‘economic man’ and the sociologists' ‘oversocialised concept’ of man rarely received much critical attention from their proponents, and now ‘rational man’ seems to have received as little practical investigation as his predecessors. He is therefore, I suspect, likely to follow them into disrepute. Indeed, he is already under some attack. Some investigators have claimed that many, extremely important, decisions are made on moral not rational grounds. Even in such a dramatic and serious matter as kidney transplantation, when the kidney is to be taken from a living donor and given to a close relative, most would-be donors “make an instantaneous split-second choice without deliberation”. They do not weigh up the pros and cons and decide accordingly but rather follow the moral imperative to donate.