The problem with proclaiming a universal truth is that someone, somewhere, lives by an opposing standard. Personally, I don't think there are fixed answers to moral questions. Views vary with each individual. Our feelings steer us into certain outlooks - liberal or conservative, conformist or rebel, etc. As Shakespeare said in II Henry IV , the wish is father to the thought.
Life is an onrushing tangle of moral puzzles.
On our editorial page, we spell out the moral stances that seem right to us - but we don't declare that they're universal maxims which everyone should obey. The choice between the assumptions makes all the difference in the way we view ourselves as a species. The split is not, as popularly supposed, between religious believers and secularists. That assertion became the cardinal premise of America's civil religion, the righteous sword wielded by Lincoln and Martin Luther King, and it endures as the central ethic binding together the diverse peoples of the United States. On religion I lean toward Deism but consider its proof largely a problem in astrophysics.