Jean-Baptiste Say introduced several important economic concepts, including distinguishing between factors of production (land, labor, capital) and introducing the concept of the entrepreneur. He is best known for "Say's Law", which states that supply creates its own demand. Say's Law was an important idea in classical economics and implied that general overproduction was impossible. It was based on ideas that savings equal investment, and that people only hold money for transactions, not as an asset. While Say's Law may have been intended to describe an equilibrium condition, it was often interpreted as being true at all times, which many classical economists like Mill disagreed with.