  We consider the question of what properties a Machine Ethics system should
have. This question is complicated by the existence of ethical dilemmas with no
agreed upon solution. We provide an example to motivate why we do not believe
falling back on the elicitation of values from stakeholders is sufficient to
guarantee correctness of such systems. We go on to define two broad categories
of ethical property that have arisen in our own work and present a challenge to
the community to approach this question in a more systematic way.
