Abstract
Euthanasia is a controversial concept since it is in some cases acceptable and in other cases not; in thinking about euthanasia the three criteria are used for making a decision: active/passive, indirect/direct ending of life and extraordinary/ordinary means; all these criteria appear to be delusory due to their vagueness and thus cannot determine which intervention is morally acceptable and which is not; there is necessary to resolve cases always concretely and the only tool for is the mental capacity named by Aristotle 'phronesis'.