> how exactly are we converging on a consensus if not from some preexisting sense of the good?
Well, there is this mechanism of imprinting our current moral settings (both declared and actually demonstrated) onto mostly blank-slate minds of the children, so that the next generation has mostly the same morals as the current one but with minor differences: so the ethics can "evolve" in time but that doesn't mean there is any end-state "consensus" they're trying to reach.
Well, there is this mechanism of imprinting our current moral settings (both declared and actually demonstrated) onto mostly blank-slate minds of the children, so that the next generation has mostly the same morals as the current one but with minor differences: so the ethics can "evolve" in time but that doesn't mean there is any end-state "consensus" they're trying to reach.