Passive and active euthanasia: what is the difference?

In order to discuss the normative aspects of euthanasia one has to clarify what is meant by active and passive euthanasia. Many philosophers deny the possibility of distinguishing the two by purely descriptive means, e.g. on the basis of theories of action or the differences between acting and omitting to act. Against this, such a purely descriptive distinction will be defended in this paper by discussing and refining the theory developed by Dieter Birnbacher in his "Tun und Unterlassen". On this basis I will suggest a new definition of active and passive euthanasia.