The platitudinous rule of thumb expressed in the title is, of course, meant to highlight the equally platitudinous fact that questions regarding what merits conservation, abolishment or unruffled tolerance tap into the realm of normative commitments and values. They are normative questions through and through. That is why the rule of thumb gains concrete meaning only against the backdrop of the pre-existing value commitments of its interpreter. Present-day discourses about a host of questions - from artificial intelligence to wars and religious identities, the climate "crisis" (which isn't a crisis because crises, per definitionem, can be overcome) to the European Union etc. - are suffused with value-talk. What is largely missing in the public clashes of diverging value commitments is open argumentative debate about what values are justifiable. Argumentative debates of this kind are largely confined to the academic fields of normative philosophical and theological ethics, to political and social theory. The talk will focus on two examples of contentious debates, one from the religious and one from the political sphere. The aim is to show how radically argumentative debate may benefit these debates.