This influential 1921 scholarly work sounded a call for intellectual freedom, which the author believed to be under attack by authoritarian tendencies in the United States. The centuries-long gains in scientific knowledge needed to be brought to bear in overcoming growing social ills and the forces of repression. The book considers Plato and Aristotle's influence on thinking, science, revolution, repression, the power of creative thought to transform the world, and the sickness of an acquisitive society.