Adam Smith was an 18th-century Scottish economist and philosopher, best known for his influential work, The Wealth of Nations. Published in 1776, this book laid the foundations for modern economic theory and introduced concepts such as the division of labor and the "invisible hand" of the market, which describes how individual self-interest can lead to positive societal outcomes. Smith is often referred to as the father of capitalism due to his ideas about free markets and competition. His thoughts on moral philosophy also contributed to the understanding of human behavior and ethics in economics, making him a key figure in both fields.