John Maynard Keynes was a British economist. He is best known as the father of modern macroeconomics. He was born in a middle-class family. He received a scholarship for Cambridge University and earned an undergraduate degree in mathematics. Though initially a supporter of Laissez-faire, Keynes started advocating for government intervention after the Great depression.
Keynes has given many theories which act as the basis of Keynesian economics. Unlike the classical economic theories, Keynes suggested that government intervention in the economy can be good and sometimes necessary to bring growth and stability.
Classical economists believed that supply creates its own demand, and thus supply is the driving force in an economy. Keynes argued that the driving principle in the economy is demand and not supply.