If such a thing as nanoethics is possible, it can only develop by confronting the great questions of moral philosophy, thus avoiding the pitfalls so common to regional ethics. We identify and analyze some of these pitfalls: the restriction of ethics to prudence understood as rational risk management; the reduction of ethics to cost/benefit analysis; the confusion of technique with technology and of human nature with the human condition. Once these points have been clarified, it is possible to take up (...) some weighty philosophical and metaphysical questions which are not new, but which need to be raised anew with respect to nanotechnologies: the artificialization of nature; the question of limits; the role of religion; the finiteness of the human condition as something with a beginning and an end; the relationship between knowledge and know-how; the foundations of ethics. (shrink)