Contemporary normative ethics is characterized by a debate between two conflic- ting theories, deontologism and utilitarianism. Until recently, this debate has essentially used arguments, objections and thought-experiments of a conceptual nature. Following the progress in neuroimagery, Joshua Greene has introduced empirical elements in the discussion : submitting several subjects to different dilemmas, in particular the trolley problem, he has examined how their brain were reacting. He concluded that deontolo- gists were drawing on their emotions, whereas utilitarians reacted more rationally, and therefore gave a better answer from a moral point of view. Deontologists reasons are even rationalizations and confabulations, rather than authentic moral reasons. Unfortu- nately, if Greene is on the right track in introducing empirical data in this debate, his conclusions are not warranted in my opinion.