The difference of natural talents in different men is, in reality, much less than we are aware of; and the very different genius which appears to distinguish men of different professions, when grown up to maturity, is not upon many occasions so much the cause, as the effect of the division of labour. The difference between the most dissimilar characters, between a philosopher and a common street porter, for example, seems to arise not so much from nature, as from habit, custom, and education.
When they came into the world, and for the first six or eight years of their existence, they were a, perhaps, a very much alike, and neither their parents nor play-fellows could perceive any remarkable difference. About that age, or soon after, they come to be employed in very different occupations. The difference of talents comes then to be taken notice of, and widens by degrees, till at last the vanity of the philosopher is willing to acknowledge scarce any resemblance. But without the disposition to truck, barter, and exchange, every man must have procured to himself every necessary and conveniency of life which he wanted. All must have had the same duties to perform, and the same work to do, and there could have been no such difference of employment as could alone give occasion to any great difference of talents.--Adam Smith Wealth of Nations, 1.2.4-5.
The quoted passage, which occurs early in Wealth of Nations in the context of the treatment of the division of labor, is at the core of so-called analytical egalitarian interpretations of Adam Smith (and methodological analytical egalitarianism [MAE], more generally, see this book by David Levy and Sandra Peart); in the passage Smith seems to side with nurture. Human cognitive differences are primarily explained by individual "habit," social "custom," and "education," as well as employment ("division of labor"). (It is methodological because when there are observed differences, Smith encourages the would be researcher to explore the social causes -- e.g., "habit, custom, and "education," as well as employment ("division of labor" etc.. -- that can account for them.) The role of employment is subtly emphasized by Smith's reference to the "first six or eight years" of a child's life; he is writing in an age of child labor, and so that labor influences the development of the child to "maturity."
Part of the point of the passage is to warn against expert overconfidence (the vanity of the philosopher) and hubris (unwillingness to acknowledge similarity). Another point is (recall) to challenge the classical conception (familiar from Plato and Aristotle) that the division of labor is the product of natural cognitive hierarchy--a position still popular (Berkeley and, as is well known, Hume flirts with it, and after Kant it gets a new lease on live in the imperialist nineteenth century). [I return to this below.] This much is familiar enough. Smith does not deny some natural, cognitive difference, but he minimizes is.
Smith pretty much asserts the position, almost like an axiom.
Smith does offer an explanation. It is peculiar and that's why, perhaps, it has escaped notice. He writes, "without the disposition to truck, barter, and exchange, every man must have procured to himself every necessary and conveniency of life which he wanted. All must have had the same duties to perform, and the same work to do, and there could have been no such difference of employment as could alone give occasion to any great difference of talents."* Smith had introduced the disposition to truck (etc.) a bit before in the first paragraph of the chapter:
THIS division of labour, from which so many advantages are derived, is not originally the effect of any human wisdom, which foresees and intends that general opulence to which it gives occasion. It is the necessary, though very slow and gradual consequence of a certain propensity in human nature which has in view no such extensive utility; the propensity to one thing for another. Whether this propensity be one of those original principles in human nature of which no further account can be given; or whether, as seems more probable, it be the necessary consequence of the faculties of reason and speech, it belongs not to our present subject to inquire. Wealth of Nations 1.2.1
Smith alludes here to a conceptual-historical distinction between (i) dispositions that are original principles of human nature, and (ii) dispositions that are acquired principles of human nature. (In the 18th century, a 'principle' is a causal explanatory ground or a fundamental (causal) property.) Smith strongly implies that 'reason and speech' belong to the original principles of human nature, and that the propensity to truck, barter, and exchange is a late, historical acquisition (a consequence of reason and speech). That in turn is one of the historical causes for the existence of the division of labor. So, without language and reason there would be no development of the disposition to trade and without this disposition there would be no division of labor. Elsewhere I have explained how Smith is developing here a form of historical explanation that, itself is a species of unintended consequence explanation indebted to Mandeville, that I have dubbed Smithian Social Explanation. This has three core elements:
- It is causal (“necessary consequence”). So, regardless of the status of propensities, the persistent triggering of these and their expression can lead to nomological outcomes such that the outcome could not be otherwise.
- It is a historical explanation. By “historical” I mean to capture three features: (a) that the stable consequence would not have been in “view” (or predictable) to observers of human nature at an early time (and, so not even capable of being intended); (b) that to be a cause here does not require temporal contiguity between the cause and the effect. c) The explanandum takes place over a very long period of time ("very slow and gradual consequence").
- Smith’s account requires that after certain consequences become visible to observer-participants they become self-reinforcing. Presumably this self-reinforcement is due to the fact that those that benefit from the cumulative consequences will help prevent backsliding from new social arrangements. (It may also be aided by the fact that those that do not so benefit will be deprived of various resources to prevent further change.) So, in the long run and in the aggregate, human propensities will produce initially unpredictable, albeit definite and determined outcomes.
Okay, now we can return to Smith's explanation of the lack of intellectual, cognitive hierarchy: “without the disposition to truck, barter, and exchange, every man must have procured to himself every necessary and conveniency of life which he wanted. All must have had the same duties to perform, and the same work to do, and there could have been no such difference of employment as could alone give occasion to any great difference of talents.” That is, absent the disposition to truck and barter -- which Smith just stipulated would likely be the case in human pre-history -- all humans must have had to do pretty much same work (as Smith considers the case in savage circumstances, WN Intro. 4, 10).
That is, Smith claims that in a counterfactual situation in which humans lack the disposition to truck (etc.), a great difference of talents would have been pointless and so absent. Given that according to Smith there are in his day still societies in which a great difference of talents is pointless, natural difference of talents ought to be limited.
It strikes me that Smith is relying on two suppressed premises. First, that humans form a single kind; as noted that was, itself, quite controversial (recall, again, alas, Hume’s “Of National Characters.”) Let's spot him the premise. Second, and more important, Smith here is clearly presupposing some kind of teleological-optimality principle, that there are no (major) natural differences in humans without a purpose. This principle has some affinity with two familiar principles, the PSR ("no effect without a cause") and, even more, the idea (found in Aristotle and Newton) that nothing is done in vain ("no cause without an effect.")** Smith does not seem to feel the need to defend the second premise.
Yet, we can make Smith's position plausible if we see what it entails about, say, Plato's position. For, Plato certainly seems to think that nature is governed by some such teleological-optimality principles. At Timaeus 28C, Plato endorses the PSR (recall "no effect without a casue") and at Timaeus 29a, he endorses some kind of (aesthetic) causal optimality principle. Now, recall that Plato's City of Pigs (or true city) in the Republic has an uncanny similarity to Smith's system of natural liberty. Socrates insists that there is a division of labor in the 'true city' that is grounded in a cognitive and physical hierarchy. From Smith's vantage point, Socrates simply assumes the causal arrow here. Smith's response to Socrates is that there is no reason to think that in the (counterfactual) state of nature prior to the City of Pigs, there would be any reason for a cognitive and physical hierarchy and so the City of Pigs could never get off the ground.