"As best as possible" does not mean that we cannot arrive at universal ethics or morality. Morality is not some ultimate truth, unless you consider a standard of right and wrong to be ultimate truth.

Moreover, there is no ought here. My analysis is purely descriptive. The only prescriptive statement I've employed is "don't do to others what you don't want done to you." This is, however, deceptive, in that it does not impose any obligation on anyone. Rather, it's an admonition of what can happen if one does act in a certain way; put another way, it illustrates estoppel and how it applies to human action.