Klaus Peter Rippe
In the public debate about assisted suicide slippery slope arguments are a common type of argument. Proponents and opponents of these arguments, however, are not always aware of their typical structure. Slippery slope arguments should not be confused with warnings claiming that a future practice will be characterized by errors and misuse. Slippery slope arguments assert that there will be an unstoppable development which will lead to an ethically inacceptable change of legal norms. Nobody who advocates a strict distinction between law and ethics may use this kind of argument. Moreover, the article shows that, contrary to widespread opinion, slippery slope arguments are part of deontological, not of utilitarian moral thinking. To restrict the right to autonomy, slippery slope arguments must meet demanding justificatory requirements. On the one hand, a specific ethical theory has to be justified. On the other hand, they must be based on plausible hypotheses regarding the causal factors which eventually lead to the disastrous development. None of the arguments currently brought forward meet these demands. Restricting the right to autonomy on that basis would not be proportionate.