Today we think of Adam Smith as an economist. But it was not his 1776 book The Wealth of Nations that made him famous. It was a work of moral philosophy, published seventeen years earlier.
The Theory of Moral Sentiments came out on 26 April 1759. It was a sensation, and made Smith a hot intellectual property. Moralists had been struggling for centuries to work out what makes some actions morally good and others morally bad. To clerics, who held great sway over the public and in intellectual debate too, the answer was plain: it was the word of God. Though of course, human life was complex, so God’s word needed a good deal of interpretation coming from those who understood it — the clerics, naturally. But then, in an age of science, there was a spreading reluctance to take the word of church leaders as definitive, and skeptics scrabbled round for other explanations. One popular theory is that human beings had a ‘moral sense’ just like smell or touch, such that they could instantly (and somehow) detect what was right and what was wrong, and distinguish them just as they distinguished red and green. But that too seemed unsatisfactory, as it was far from obvious how such a supposed sense worked, and why different people had different perceptions of right and wrong.
There were other theories too. But Smith’s breakthrough was to explain that our moral judgement stem from our very psychology as social creatures. Human beings, he suggested, are born with a natural ’sympathy’ (today we would say ‘empathy’) for other members of their species. They are distressed by the pain of others, and uplifted by the joy of others. And that is what helps us shape our behaviour in ways that produce a general good. We enjoy the praise that comes from others when we do something ‘right’ and are troubled by the disapprobation of others when we do something ‘wrong’.
Smith was writing exactly a century before Darwin’s 1859 classic The Origin of Species, so he did not have advanced evolutionary theory to help him explain why we should have this rather useful social psychology. He put it down to ‘Providence’. His friend David Hume had struggled with similar problems in the last section of his own Treatise of Human Nature. But Smith had no doubt that this social psychology persisted because it brought our species a general benefit. He knew it must be something like what we now call ’natural selection’. Honour among thieves and all that: if we started behaving wickedly to each other, our society would break down pretty quickly.
The Theory of Moral Sentiments was an instant and international best seller. Not only was the central idea sensational, but the prose (for the time) elegant and Smith’s rubbishing of other (often pompous) moral theorists was thought exquisite. It brought Smith to the attention of Charles Townsend, a leading intellectual and British government official, who asked Hume to introduce them. It led to Smith being plucked out of Glasgow University and hired, for a very generous lifetime income, to become tutor to Townsend’s young stepson, the Duke of Buccleugh. The tutoring took Smith on the grand tour of Europe with his the young aristocrat, where he was able to talk with some of the leading European intellectuals and to see the different industries and ways of working on the Continent. He started thinking about a new book: not this time on moral philosophy but on another part of human social psychology — economics. It took him over a decade to turn his ideas and the vast mountain of economic facts he assembled into what would become The Wealth of Nations. And with that, his fame was assured, not only in his own time, but in centuries to come.