Adam Smith (1723–1790) was a Scottish philosopher who is best known for his book The Wealth of Nations, which had a profound influence on modern economics and concepts of individual freedom. He was a professor of logic at Glasgow University, as well as the chair of moral philosophy. His lectures covered the field of ethics, rhetoric, jurisprudence, and political economy. In 1759, he published his Theory of Moral Sentiments, which embodies some of his Glasgow lectures. In 1776, he published The Wealth of Nations, which covered such concepts as the role of self-interest, the division of labor, the function of markets, and the international implications of a laissez-faire economy. Smith is most often recognized for the expression "the invisible hand," which he used to demonstrate how self-interest guides the most efficient use of resources in a nation's economy, with public welfare coming as a by-product.