In his classic book On Liberty, the nineteenth-century British philosopher John Stuart Mill urged that man strive to become “a progressive being.” Mill defined progressivism as the cultivation of individuality; to live progressively, he wrote, a man requires personal freedom. But Mill and other liberal philosophers of his era also saw that individual development could not happen without a community. This recognition was the starting point of progressivism as a philosophy of government. As the longtime Oxford professor Alan Ryan puts it, modern liberalism’s aims are to “emancipate individuals from the fear of hunger, unemployment, ill health, and a…