I’m halfway through J. B. Schneewind’s The Invention of Autonomy: A History of Modern Moral Philosophy. “Modern” in this case doesn’t mean “contemporary”. Philosophers generally consider Rene Descartes to be the founder of modern philosophy and he died in 1650. Schneewind’s book concludes with Immanuel Kant, who died in 1804. (Philosophy isn’t one of those disciplines that leaves the past behind.)
Moral philosophy hasn’t stood still since Kant, but he’s still a very important figure. Kant argued that in order to act ethically, we must subject ourselves to a moral principle (the Categorical Imperative) that we freely and rationally adopt. We must be autonomous agents, not someone else’s followers.
However, as Schneewind tells the story in the first half of The Invention of Autonomy, moral philosophers in the early modern period were deeply concerned with an issue that wasn’t modern at all. Plato presented the problem in one of his early dialogues, Euthyphro: “Is the pious loved by the gods because it is pious, or is it pious because it is loved by the gods?”. Or, in modern form, “Is the morally good commanded by God because it’s morally good, or is it morally good because it’s commanded by God?”.
Not surprisingly, there were a variety of answers to this question. Some philosophers and theologians argued in favor of “intellectualism”: God commands what is morally good because God recognizes the principles of morality. It isn’t in God’s power or nature to prefer the immoral to the moral. Richard Cumblerland, for example, argued that morality is rational and God is supremely rational. Hence, God’s commands must be the right ones. God cannot make mistakes.
But if God couldn’t have issued different commands, doesn’t that limit God’s power? And doesn’t it mean that morality somehow stands apart from God? It would seem that God might not even be necessary for morality. Concerns like that convinced some to argue for “voluntarism”: God’s commands define morality. God voluntarily chose the morality we have, so what is moral or immoral would have been different if God had chosen differently. Descartes was an extreme voluntarist, for example. Schneewind notes that, according to Descartes,
Eternal verities must depend on God’s will, as a king’s laws do in his country. There are eternal truths, such as that the whole is greater than the part; but they would not be true unless God had willed them to be so .
Maybe it made sense for the early modern philosophers to spend so much time trying to figure out what God was thinking, and whether God could have chosen differently, and how morality and God are related. Living in a world subject to the idiosyncratic decisions of kings and queens, it must have been natural to view morality in terms of divine commands.
Eventually, however, the intellectualist side prevailed (to the extent that God remained in the picture at all). It became clear that morality and religion aren’t necessarily connected. All that speculating and arguing about the relationship between God and morality was an enormous waste of time. If you don’t believe me, read the first half of The Invention of Autonomy.