If all approaches to life are equally legitimate, how can you possibly say it's better to do one thing over another? How can you decide what the "right" thing is to do?
The answer is, you can't — at least not with pluralism alone. But with the emergence of an integral worldspace, answers begin to appear. This integral worldspace is the first to notice the developmental spectrum of human consciousness. The higher the level of interior development, the more perspectives that are taken into account, the more ethical that decision is attempting to be. Therefore, the legitimating force for ethics at integral levels of development is evolution itself, as increasing levels of complexity and consciousness appears to be the direction the kosmos is headed.
(Roger Walsh and Ken Wilber written by Colin Bigelow)