Over the past several weeks, I’ve blogged about theistic metaethical realism and whether moral truth require God’s existence. In this post, I will briefly describe an additional problem for those theories according to which our moral duties are identical to God’s commands. In addition, I will sketch a possible solution and illustrate one of its pitfalls.
Divine Command Theory (DCT) is the view that whatever we ought to do, we ought to because God commands it. DCT identifies God’s commands with our moral obligations. Famously, DCT is subject to the Euthyphro Dilemma — does God command us to do x because x is moral or is x moral because God commands us to x? The former possibility denies DCT, but the latter is comparatively implausible because it renders our moral duties arbitrary. Theists have provided various solutions — for example, that our moral duties issue forth from God’s essence, which is identified with the Good — and so I put aside the Euthyphro Dilemma in this essay to focus on a different problem.
Consider modus ponens:
1. If P then Q.
3. Therefore, Q.
We say modus ponens is valid because the truth of the premises guarantees the truth of the conclusion. In other words, there is no way for 1 and 2 to be true, but 3 false. We can examine the truth table for all three propositions and notice whenever ‘If P then Q’ and ‘P’ are true, ‘Q’ is also true. We refer to valid inferences as truth preserving; i.e. they preserve the truth of the premises.
Meta-ethical theories can be broadly split in two categories: cognitive theories, according to which moral statements can be true or false, and non-cognitive theories, according to which moral statements can be neither true nor false. For example, a non-cognitive theory might indicate ‘murder is wrong’ really means ‘Boo! Murder!’. Booing is neither true nor false, so ‘murder is wrong’ would evaluate to neither true nor false. Notice what happens when we assume a non-cognitive theory and try modus ponens:
1′. If murder is wrong then ordering Tom to murder Carly is wrong.
2′. Murder is wrong.
3′. Therefore, ordering Tom to murder Carly is wrong.
Intuitively, we want to say that 3′ follows from 1′ and 2′. But how could 3′ follow from 1′ and 2’? The inference is no longer valid because 2′ does not evaluate to either true or false. We might try to develop some new notion resembling validity (shmvalidity?). Let’s attempt to do so. Notice validity relies on preserving something or other about the premises and that, whatever is preserved, determines the conclusion uniquely. For ordinary declarative sentences — where each sentence evaluated to true or false — the truth value was preserved. But because non-cognitive theories posit that moral statements lack truth values, there is no truth value to be preserved. Notice that what allowed the truth value to be preserved in the case of ordinary sentences was that the meaning was preserved; i.e. P means the same thing in 1 as P meant in 2. Thus, we might posit that although ‘murder is wrong’ does not evaluate to true or false, ‘murder is wrong’ does preserve its meaning from 1′ to 2′; if so, meaning preservation would ensure shmvalidity.
Unfortunately, ‘murder is wrong’ does not actually mean the same thing in 1′ and 2′ because, in 1′, ‘murder is wrong’ is mentioned but not asserted, whereas, in 2′, ‘murder is wrong’ is asserted. While it’s not clear what ‘murder is wrong’ means in the first sentence, the statement ‘If Boo! Murder! then ordering Tom to murder Carly is wrong’ is clearly not grammatical.
The problem generalizes: on non-cognitive theories, we cannot make sense of our usual rules of deductive inference. Moreover, on non-cognitive theories, we do not know how to understanding meaning of a statement in terms of its parts. Problems of this sort are referred to as the Frege-Geach Problem. Those who endorse non-cognitivism in ethics continue to hunt for a semantic theory to resolve the Frege-Geach Problem, but have been unsuccessful thus far. I am skeptical that they will ever succeed, so I regard non-cognitive theories as fairly implausible.
However, on one interpretation, DCT is a non-cognitive theory. Prescriptivism is the view that moral statements are commands; call Divine Prescriptivism the view that moral statements are God’s commands. On this view, ‘murder is wrong’ is equivalent to God’s statement ‘do not murder!'; moreover, prescriptivism, as a non-cognitive theory, is subject to the Frege-Geach Problem. Divine Prescriptivism, as a version of prescriptivism, inherits the Frege-Geach Problem.
Luckily for the DCT advocate, Divine Prescriptivism is not the only view on the market. While God’s commands might not be truth evaluable, whether or not God issued any particular command is true or false. For example, ‘do not murder!’ is neither true nor false, but ‘God told us not to murder’ can be true and false. DCT advocates claim only that moral duties are identical to God’s commands, not that moral statements are identical to God’s commands. Moreover, we do not ordinarily think our moral duties are propositions, so it’s not that surprising that our moral duties fail to be truth evaluable or that we cannot combine moral duties together to build complicated propositions.
Nonetheless, I find the identification of commands and duties fairly incomprehensible; can anyone — even God — speak duties? If duties are not speech acts, then they cannot be spoken, even by a being who can perform all logically possible tasks. The better option is to say that the commands of worthy authorities somehow enter us into various duties and not that the commands are identical to the duties. Consider promises. If I say, “I promise to feed the cat”, my statement isn’t somehow identical to my duty to feed the cat. Instead, we might say that verbalizing a promise enters me into an obligation to maintain the promise. Likewise, a worthy authority commanding us to x might enter us into an obligation to x, but it is difficult to see the command, itself, as identical to the obligation.
Yet, supposing that commands and duties were not identical, but the former somehow gives rise to instances of the latter, requires an additional moral duty; e.g. one should obey the commands of worthy authorities. The DCT advocate maintains that all of our duties arise from God’s commands, so our duty to obey the commands of worthy authorities must also arise from God’s commands. Yet if our duty to obey the commands of worthy authorities arose from God’s commands, there must be a further duty to obey that command. An infinite regress ensues. Nonetheless, perhaps God, as an omnipotent being, can issue an infinite number of commands; even then we would need a further principle — that we should obey that infinite regress of commands! So, there should be at least one duty that is not created by a divine command, but then DCT is false.
Thus, DCT advocates need not maintain Divine Prescriptivism, but the most plausible alternative is deeply problematic. I suggest to the DCT advocate they explain what, on their view, the metaphysical relationship between commands and duties is supposed to be.