I have argued that Smith cannot be characterized as a rights‐​based libertarian for whom liberty is the sole guiding principle. After all, he advocates many exceptions that violate liberty. He also does not fit in the liberty‐​only camp because his moral philosophy precludes systems built on a single ideal. In the last part of The Theory of Moral Sentiments he criticizes Epicurus and other philosophers for over‐​simplifying the world to fit a single principle.

But neither should we think of Smith as treating liberty as simply one among many values like equality, utility, propriety, order, prudence, or prosperity. Left Smithians tend to interpret Smith this way and thereby water down the importance of liberty. They have nothing against liberty, of course, but only as long as these other values are being satisfied. They miss that liberty, and its duty of commutative justice (“abstaining from what is another’s”), is the most widespread and important theme in Smith’s works—both by the number of times he talks about liberty and by his eloquence in doing so.

The third alternative is that Smith thought liberty was the most important value, but had to be weighed against other important values. Although liberty was essential, Smith was willing to restrict it in a few limited instances. He presumed that liberty was the default. Contravention of it requires compelling evidence and strong arguments. That “presumption of liberty” runs throughout Smith’s work and remains an attractive political philosophy today.

But what warrants this presumption of liberty? There are three main postulates. First, a firm belief that individuals will generally pursue their own interests and improvement, as well as that of their family and friends, on their own initiative. Smith took it as a given that people will seek to better their own condition. Second, a belief that markets generally bring about a prosperous spontaneous order. “[W]ithout the assistance and cooperation of many thousands, the very meanest person in a civilized country could not be provided” with basic food, clothing, or shelter. Third, a deep skepticism of the knowledge possessed by and incentives facing politicians and bureaucrats.

Let me stress the word “generally” in the first two warrants. The problem with making the liberty principle axiomatic, that is not having any exceptions, is that it becomes brittle. A single successful counter‐​example undermines the entire position. One major advantage of treating the liberty principle as a maxim (a presumption), is that it leaves room for exceptions. We can still take a strong stance in favor of liberty without having to argue that people always make wise choices or that markets never create problems or unpleasant side effects.

Smith argues that individuals have the best knowledge and incentives for taking care of themselves and those they care about: “Every man, as the Stoics used to say, is first and principally recommended to his own care; and every man is certainly, in every respect, fitter and abler to take care of himself than of any other person.” We have habitual sympathy towards those who are near us, either physically or relationally. Although many people are fond of saying that they will the good of all men equally, and that we should actively work to improve everyone’s life through government, Smith thinks they are misguided: