John Rawls was one of the most important philosophers of the 20th century and the most significant contributor of that century to the philosophy of liberalism. Born in 1921 in Baltimore, Maryland, Rawls initially considered a career in the Episcopalian priesthood, but his studies were interrupted by the outbreak of the Second World War. Experiencing the horrors of war, especially seeing the city of Hiroshima shortly after the US atomic bombing, convinced Rawls to become an atheist, and he shifted his focus from theology to philosophy. Following the war, he received his PhD from Princeton University and then taught at Cornell and the Massachusetts Institute of Technology before arriving at Harvard, where he taught for nearly 40 years until his death in 2002.

Rawls’s career and life overlapped with a critical period in the history of liberalism. The classical liberalism of the Enlightenment sought to limit the powers of government and carve out the widest possible space for individuals to exercise their talents freely. With the Industrial Revolution, liberal governments lacked the power to regulate powerful businesses, leading to tremendous inequalities that belied the promise of liberty for all. Socialism then emerged as the great challenger to liberalism, proposing a much more expansive government to ensure basic levels of social equality.