Cultural Ethical Relativism

Reading Bioethics today, I came across a topic that never ceases to annoy me, that I bring up again because I do have difficulty understanding your position on it: relativism.

Specifically in this case, cultural relativism, and retrograde relativism.

For the latter...Remarks such as "It was a different world then" and "We can't judge the past by contemporary standards" are revealing. The assumption must be that the validity of moral judgements depends upon their cultural context, and that cultural contexts change over time. In other words, skepticism about retrospective moral judgments is simply a special case of the more general position known as cultural ehthical relativism. Acoording to this position, the validity of all moral udgments is culturally relative. This position implies that moral judgments about the past are invalid if they are applied across cultural boundaries.

According to cultural ethical relativism, moral judgments applied across cultural boundaries are invalid because moral judgments can be justified only by reference to shared values, and shared values are found only within a particular culture. We cannot