In Sinclair Lewis's book "It Can't Happen Here," the author emphasizes the significance of a free and critical spirit in achieving valuable progress in society. He argues that the essence of advancement lies in the ability to inquire and challenge existing norms, asserting that maintaining this intellectual freedom is paramount, more than any structured social system. Without this spirit, society risks stagnation and regression.

Lewis warns that individuals who adhere strictly to tradition and those who embrace brutality can suppress scientific inquiry and critical thinking. This suppression poses a grave threat to intellectual freedom and the potential for innovation, suggesting that safeguarding a vibrant culture of questioning and exploration is essential to avoid a bleak future dominated by dogma and ignorance.