&quot;He essentially defines an act as &quot;good&quot; if it&#x27;s a net increase in human happiness and well-being.&quot;<p>John Rawls, one of the foremost liberal philosophers of our time spends the bulk of his most famous book arguing agains that very idea.  My take away is that from a secular perspective it is impossible to argue from first principles what is good and bad.  It&#x27;s also obviously not a very strong argument.  If there was a tiny country that did dispicable things to it&#x27;s citizens but it had nuclear weapons, by this argument, the &#x27;good&#x27; thing would be to allow those citizens to continue to suffer rather then have the world intervene and potentially be obliterated in a nuclear war.  However, the citizen&#x27;s of that country would still be correct to say that the rest of the world was unjust.