In the matter of health, the care of a patient is not the same as that of a population. With regards to medical ethics, it is essential to differentiate that which is for the patient's well being, and that which relies on knowledge and responsibility, the principle of which is not to do harm. The health sector has become an important economic actor in our society. Any decision made must take into account the principle of well being and responsibility. The physicians' role, when making a decision, is to integrate not only the patient's quality of life but also the Public Health aspects, and to apply these notions to a well thought-out choice and shared with the patient. A triangle can be constructed with, at its base the percentage of the population concerned and at its peak the cost per beneficiary. This triangle can then be segmented at varying distance from its base, in current decisions applicable to the greatest number, and depending on the amount of resources available.