Adam Smith held that humans are distinctively dependent on one another’s labour. We are reliant upon, and make differential contributions to, a system in which the total quantity of labour that contributes to each of our flourishing is divided amongst us. Such a system relies for its proper functioning upon individual contributors both trusting others to do their share and also being trustworthy, in pulling their own weights. Smith raises the question whether the greater role in underwriting the required pattern of trust and trustworthiness is played by benevolence or by self-interest. He suggests that, in general, the system is lubricated by self-interest rather than benevolence.
“In almost every other race of animals, each individual, when it is grown up to maturity, is entirely independent, and in its natural state has occasion for the assistance of no other living creature. But man has almost constant occasion for the help of his brethren, and it is in vain for him to expect it from their benevolence only. He will be more likely to prevail if he can interest their self-love in his favour, and shew them that it is for their own advantage to do for him what he requires of them. Whoever offers to another a bargain of any kind, proposes to do this. Give me that which I want, and you shall have this which you want, is the meaning of every such offer; and it is in this manner that we obtain from one another the far greater part of those good offices which we stand in need of. It is not from the benevolence of the butcher the brewer, or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity, but to their self-love, and never talk to them of our own necessities, but of their advantages.” (Adam Smith, 1776, Wealth of Nations, Book I, Chapter II, ‘Of the principle which gives occasion to the division of labour’.)
On this view, our reasonable reliance on the baker to provide us with cakes is based upon our knowledge of their reciprocal reliance on our cake-custom. It is not based upon our knowledge of their benevolence—of their recognition that cake will make our lives go better together with their positive responsiveness to that recognition on grounds, for example, of our shared humanity.
One question we might raise here concerns the idea that such reliance is distinctive of humans. Perhaps, for example, the social behaviours of some animals, or even insects, might count as forms of the social division of labour. We might think that that is not important, and that what really matters to Smith is rather the obviously correct claim that human labour is now divided. However, understanding the bases of similar cases in other areas of the animal kingdom, should they exist, might well be relevant to understanding the actual bases of the system realised by humans. Another question concerns the extent to which the human system is really underwritten mainly by self-interest, rather than benevolence. While it’s plausible that some people are motivated by self-interest for much of the time, and many people are so motivated for some of the time, we shouldn’t allow that to blind us to the possibility that our own motivations, and others’, may stem predominantly from benevolence.
Suppose that our motivations for doing what we tell others we will do were mainly, or fundamentally, self-interested. In that case, it would be natural to expect that, where motivation by self-interest lapsed, so too would lapse any motivation towards fulfilment of one’s expressed intention. More carefully, if one retained any motivation towards fulfilment, one would expect it to be explained by appeal to habit, or to some other form of generalisation from the more basic, self-interested case, rather than by appeal to reason.
In an earlier discussion, Smith reflects on a case in which someone promises under coercion. The reflection aims to uncover the proper moral response to one who fails to keep such a promise.
“To give a trite example; a highwayman, by the fear of death, obliges a traveller to promise him a certain sum of money. Whether such a promise, extorted in this manner by unjust force, ought to be regarded as obligatory, is a question that has been very much debated.” (Adam Smith, 1759, The Theory of Moral Sentiments, Section IV, part II.)
Now a natural thought here is that, although there are self-interested grounds for promising the highwayman the sum of money—for instance, that one prefers not to be shot—there will only be self-interested grounds for keeping that promise insofar as the threat of retribution remains active. Once the immediate threat has abated—once the traveller has returned to the safety of the city, say—it is natural to think that there will be no motive from self-interest for returning to the scene of the crime with the promised sum of money. However, Smith appears to suggest that in a case of that sort, some motivation would remain for keeping the promise:
“It is to be observed, however, that whenever such promises are violated, though for the most necessary reasons, it is always with some degree of dishonour to the person who made them.” (Adam Smith, The Theory of Moral Sentiments, Section IV, part II.)
Smith suggests, then, that where the straightforward motivation from self-interest has lapsed, one might nonetheless be motivated by one’s honour, or by considerations of one’s honour.
There are three obvious potential explanations of how we are to understand Smith’s account here. The first potential explanation appeals to the idea of a generalisation of one’s habitual, self-interested response to more ordinary cases in which one makes a promise. One has become so habituated to meeting the demands of self-interest by keeping one’s promises in cases where doing so will induce others to reciprocate that one now feels a tug of psychic dissonance in cases in which one fails to do so.
The second potential explanation is less direct. In order for the institution of promising successfully to figure in the self-interested division of labour, it must be a matter of general and mutual recognition that promises will be kept. Crucially, it must be a matter of general and mutual recognition that promises will be kept even in those cases in which doing so fails to service the keeper’s self-interested motivations. Hence, an individual’s failure to keep a promise, even in such cases, damages their ability to exploit the institution in the future—perhaps, at the limit, by doing violence to the institution itself. Since it is in the individual’s interest to preserve a capacity to exploit the institution, it is in their interest to keep their promises even in cases like that of the highwayman, albeit in a way that, in such cases, is outweighed by other considerations.
The third potential explanation is quite different. According to the third explanation, there is an operative motive associated with keeping one’s promises that is not reducible to considerations of self-interest. Rather, it is a motive deriving from, or recognised on the basis of, an irreducible moral virtue: a virtue of (or akin to) honour. Again, the operative motive may be one that allows that one need not in fact keep one’s promise in the case of the highwayman. But that is consistent with there being a genuine moral loss in the case in which one doesn’t keep one’s promise, albeit a loss that may be condoned. Plausibly, the loss attends, not the simple failure to keep one’s promise, but rather the combination of one’s promising and then not keeping one’s promise. On this type of view, the highwayman in effect forced one to be immoral.
I leave open which, if any, of those explanations is correct. If none is, it will be a further question what the correct explanation is, and whether the correct explanation will endorse Smith’s view that failing to keep a promise to the highwayman constitutes a moral loss.
Smith’s case of the highwayman is discussed by Bernard Williams in chapter 5 of his book Truth and Truthfulness (Princeton, NJ: Princeton University Press, 2002) and also by Thomas Scanlon in chapter 7 of his book What We Owe to Each Other (Cambridge, Mass.: Harvard University Press, 1998).