APA (7th ed.) Citation

Santayana, G. (2005). The Life of Reason The Phases of Human Progress. Project Gutenberg.

Chicago Style (17th ed.) Citation

Santayana, George. The Life of Reason The Phases of Human Progress. Project Gutenberg, 2005.

MLA (9th ed.) Citation

Santayana, George. The Life of Reason The Phases of Human Progress. Project Gutenberg, 2005.

Warning: These citations may not always be 100% accurate.