Thomas Robert Malthus (1766-1834) was an English cleric whose ideas, as expounded in his most famous work the Essay on the Principle of Population, caused a storm of controversy. In this Very Short Introduction, Donald Winch explains and clarifies Malthus's ideas, assessing the profound influence he has had on modern economic thought. Concentrating on his writings, Winch sheds light on the context in which he wrote and why his work has remained controversial. Looking at Malthus's early life as well as the evolution of his theories from population to political economy, Winch considers why and how Malthus's writings have been so influential in the thought of later figures such as Darwin and Keynes.