Economics in One Lesson is an introduction to free market economics written by Henry Hazlitt and first published in 1946. It is based on Frédéric Bastiat's essay Ce qu'on voit et ce qu'on ne voit pas (English: "What is Seen and What is Not Seen". Economics in One Lesson is an essential guide to the basics ofeconomic theory. A fundamental influence on modern libertarianism, Hazlitt defends capitalism and the free market from economic myths that persist to this day.