The first thesis, the diversity thesis, or what may simply be called cultural relativism is an anthropological thesis, registering the fact that moral rules differ from society to society."

The diversity thesis is a "descriptive" (not "prescriptive", not normative) claim about what societies accept, not a thesis about moral "validity" or moral truth.

The dependency thesis asserts that the "validity" or bindingness or truth of a moral principle "depends on" its acceptance.

Roughly, the dependency thesis can be stated as a pair of generalized conditional statements:

If a moral principle P is accepted by (society or individuals) x, then P is valid (or binding) for x; and

If a moral principle P is not accepted by (society or individuals) x, then P is not valid (or binding) for x.