> The human body is so complex. We can try to gather some knowledge by means of experiments, models and statistical data, but we must realize that the scientific method is a human endeavour and is therefore imperfect by definition. Being a scientist (I study cosmology), I feel deeply embarrassed whenever I hear people professing their irreducible faith in «science».

Hear, hear! And 'faith' in this case is indeed the right term... I have a similar reaction to those who are convinced there is a bright line between 'hard' and 'soft' sciences. Strictly speaking, you can never accumulate all the evidence.