Many of Hume's political ideas, such as limited government, private property when there is scarcity, and constitutionalism, are first principles of liberalism. Thomas Jefferson banned the History from University of Virginia, feeling that it had "spread universal toryism over the land." By comparison, Samuel Johnson thought Hume to be "a Tory by chance [...] for he has no principle. If he is anything, he is a Hobbist." A major concern of Hume's political philosophy is the importance of the rule of law. He also stresses throughout his political essays the importance of moderation in politics, public spirit, and regard to the community.

Throughout the period of the American Revolution, Hume had varying views. For instance, in 1768 he encouraged total revolt on the part of the Americans. In 1775, he became certain that a revolution would take place and said that he believed in the American principle and wished the British government would let them be. Hume's influence on some of the Founders can be seen in Benjamin Franklin's suggestion at the Philadelphia Convention of 1787 that no high office in any branch of government should receive a salary, which is a suggestion Hume had made in his emendation of James Harrington's Oceana.

The legacy of religious civil war in 18th-century Scotland, combined with the relatively recent memory of the 1715 and 1745 Jacobite risings, had fostered in Hume a distaste for enthusiasm and factionalism.[citation needed] These appeared to him to threaten the fragile and nascent political and social stability of a country that was deeply politically and religiously divided.[failed verification] Hume thought that society is best governed by a general and impartial system of laws; he is less concerned about the form of government that administers these laws, so long as it does so fairly. However, he also clarified that a republic must produce laws, while "monarchy, when absolute, contains even something repugnant to law."

Hume expressed suspicion of attempts to reform society in ways that departed from long-established custom, and he counselled peoples not to resist their governments except in cases of the most egregious tyranny. However, he resisted aligning himself with either of Britain's two political parties, the Whigs and the Tories, explaining that "my views of things are more conformable to Whig principles; my representations of persons to Tory prejudices".

The scholar Jerry Z. Muller argues that Hume's political thoughts have characteristics that later became typical for American and British conservatism, which contain more positive views of capitalism than conservatism does elsewhere. Canadian philosopher Neil McArthur writes that Hume believed that we should try to balance our demands for liberty with the need for strong authority, without sacrificing either. McArthur characterises Hume as a "precautionary conservative," whose actions would have been "determined by prudential concerns about the consequences of change, which often demand we ignore our own principles about what is ideal or even legitimate." Hume supported the liberty of the press, and was sympathetic to democracy, when suitably constrained. American historian Douglass Adair has argued that Hume was a major inspiration for James Madison's writings, and the essay "Federalist No. 10" in particular.

Hume offered his view on the best type of society in an essay titled "Idea of a Perfect Commonwealth", which lays out what he thought was the best form of government. He hoped that "in some future age, an opportunity might be afforded of reducing the theory to practice, either by a dissolution of some old government, or by the combination of men to form a new one, in some distant part of the world". He defended a strict separation of powers, decentralisation, extending the franchise to anyone who held property of value and limiting the power of the clergy. The system of the Swiss militia was proposed as the best form of protection. Elections were to take place on an annual basis and representatives were to be unpaid. Political philosophers Leo Strauss and Joseph Cropsey, writing of Hume's thoughts about "the wise statesman", note that he "will bear a reverence to what carries the marks of age." Also, if he wishes to improve a constitution, his innovations will take account of the "ancient fabric", in order not to disturb society.

In the political analysis of philosopher George Holland Sabine, the scepticism of Hume extended to the doctrine of government by consent. He notes that "allegiance is a habit enforced by education and consequently as much a part of human nature as any other motive."

In the 1770s, Hume was critical of British policies toward the American colonies and advocated for American independence. He wrote in 1771 that "our union with America…in the nature of things, cannot long subsist."

Hume expressed his economic views in his Political Discourses, which were incorporated in Essays and Treatises as Part II of Essays, Moral and Political. To what extent he was influenced by Adam Smith is difficult to assess; however, both of them had similar principles supported from historical events. At the same time Hume did not demonstrate concrete system of economic theory which could be observed in Smith's Wealth of Nations. However, he introduced several new ideas around which the "classical economics" of the 18th century was built. Through his discussions on politics, Hume developed many ideas that are prevalent in the field of economics. This includes ideas on private property, inflation, and foreign trade. Referring to his essay "Of the Balance of Trade", economist Paul Krugman (2012) has remarked that "David Hume created what I consider the first true economic model."

In contrast to Locke, Hume believes that private property is not a natural right. Hume argues it is justified, because resources are limited. Private property would be an unjustified, "idle ceremonial," if all goods were unlimited and available freely. Hume also believed in an unequal distribution of property, because perfect equality would destroy the ideas of thrift and industry. Perfect equality would thus lead to impoverishment.

David Hume anticipated modern monetarism. First, Hume contributed to the theory of quantity and of interest rate. Hume has been credited with being the first to prove that, on an abstract level, there is no quantifiable amount of nominal money that a country needs to thrive. He understood that there was a difference between nominal and real money.

Second, Hume has a theory of causation which fits in with the Chicago-school "black box" approach. According to Hume, cause and effect are related only through correlation. Hume shared the belief with modern monetarists that changes in the supply of money can affect consumption and investment.

Lastly, Hume was a vocal advocate of a stable private sector, though also having some non-monetarist aspects to his economic philosophy. Having a stated preference for rising prices, for instance, Hume considered government debt to be a sort of substitute for actual money, referring to such debt as "a kind of paper credit." He also believed in heavy taxation, believing that it increases effort. Hume's economic approach evidently resembles his other philosophies, in that he does not choose one side indefinitely, but sees gray in the situation.