We turn next to a different defense that the eudaemonist might make, one that derives from the Stoics. The idea is that the notion of reason brings impartiality with it, and so our good as rational beings requires that we follow the moral law. This is the sort of idea that says achieving the good of all, as you do if you act impartially, just is achieving your own good properly understood.

The key is “properly understood.” The good or “benefit” has to be distinguished from the merely “convenient.” Goods when properly understood are shared or common to the excellent. We have from the Stoics a “double-source” view of motivation. They distinguish motivation by self-concern and motivation by concern for others. Both of these develop. They have a technical term for this that we can translate “appropriation.” We can distinguish two kinds of appropriation: personal and social. The first is the development that takes us from self-preservation to valuing reasoning as a way to get the things that fit our nature, such as health and wealth, and then to valuing reason in its own right. The second is the development through progressively wider social groupings, until one cares for every human being.

This is a double-source theory in a sense, but not in the sense introduced earlier. This is because the Stoics were eudaemonists, and held that both forms of appropriation enable one to see better a single thing, one’s own chief good, which remains the source of all motivation. But here’s a problem: It’s true that if I already see my aunt, for example, as worth the same as my mother, then I will see that a benefit to my aunt is worth the same as a benefit to my mother. But if I don’t already see this, it is unclear how reason can require me to see it. What the argument needs to show is that it’s irrational to prefer benefiting those near to those far. Why should reason move to this? In fact, for that matter, why should reason prevent me preferring benefiting myself to benefiting someone else?

A contemporary philosopher who makes an argument rather similar to the Stoic one is Peter Singer. He thinks that we can get on an “escalator of reason,” and find ourselves moving toward the standpoint of the impartial spectator or ideal observer. From this standpoint, which Sidgwick calls the point of view of the universe, it makes no difference to the moral decision whether the interest being served is mine or someone else’s. But Singer also accepts from Sidgwick that reason allows me to get off the escalator at any point. He denies the argument he attributes to Kant that reason by its nature requires universalizing, or willing the maxims of our actions as universal laws. The point is that Singer acknowledges that we can’t get a convincing argument from the nature of reason itself for moving to the moral point of view. There is nothing irrational in itself, he says, about preferring oneself.

A number of other contemporary philosophers have tried a similar strategy. One is Korsgaard, whose conception of the “normative question” Hare’s been using all along. She thinks that Kant intended the formulation of the Categorical Imperative in terms of universal law to give us, all by itself, the moral law. But she thinks Kant failed to see that prescribing universal law does not yet settle the question of the domain over which the law of the free will must range. The domain could be the desires of the moment, for example, or of the agent’s whole life. She thinks she can provide an argument for extending the domain over every rational being. She starts from the observation that what separates humans from other animals is their ability to act on the basis of a self-conception, what she calls a “practical identity,” conceptions like “sister” or “philosopher.” She thinks practical identities create unconditional obligations, and this is one place where her view can be questioned.

Cohen raises the case of the idealized Mafioso. Not doing some horrible deed might result in his loss of identity, yet surely we are better off not having to say that the Mafioso has an obligation to do the horrible thing. Korsgaard qualifies her claim by adding that the Mafioso has a deeper obligation to give up his immoral role. This is because the activity of reflection has rules of its own, and one of them is the rule that we should never stop reflecting until we have reached a satisfactory answer, one that admits of no further questioning. Following this rule would lead the Mafioso to morality.

Hare thinks the argument breaks down here. There is nothing in the nature of reflection as such that requires giving priority to the way humans are the same (namely, that they have practical identities) over the ways they are different. Even if it’s true that valuing your practical identity implies valuing the human capacity to set a practical identity, you can still value your differences from other human beings more. So, alas, it’s possible to be a fully reflective Nazi. To be sure, we can always define “reflection” or “reason” in such a way that it brings morality with it. But there does not seem to be a morally neutral account of reason or reflection that allows us to deduce morality from it. The history of attempts to give such an argument is not encouraging. If, though, we accept that the moral law is God’s command, then we can see a way to argue for it from the premise that reason tells us that, if there is a God, God is to be loved and obeyed (a proposition, recall, Scotus argued, can be known from its terms).

Image: By Paolo Monti - Available in the BEIC digital library and uploaded in partnership with BEIC Foundation.The image comes from the Fondo Paolo Monti, owned by BEIC and located in the Civico Archivio Fotografico of Milan., CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48067347