The Theory of Moral Sentiments is a 1759 book by Adam Smith. It provided the ethical, philosophical, psychological, and methodological underpinnings to Smith's later works, including The Wealth of Nations (1776), Essays on Philosophical Subjects (1795), and Lectures on Justice, Police, Revenue, and Arms(1763) (first published in 1896).

Adam Smith (16 June 1723 NS (5 June 1723 OS) – 17 July 1790) was a Scottish moral philosopher, pioneer of political economy, and key Scottish Enlightenment figure.

Smith is best known for two classic works: The Theory of Moral Sentiments (1759), and An Inquiry into the Nature and Causes of the Wealth of Nations (1776). The latter, usually abbreviated as The Wealth of Nations, is considered his magnum opus and the first modern work of economics. Smith is cited as the "father of modern economics" and is still among the most influential thinkers in the field of economics today.