Pyotr Lavrovich Lavrov (June 2 (June 14 N.S.), 1823 – January 25 (February 6 N.S.), 1900) was a prominent Russian philosopher, publicist, and sociologist. He was well-versed in natural science, history, logic, philosophy, and psychology. He also became an instructor in mathematics for two decades. Lavrov was also a prolific writer for more than 40 years. His works include The Hegelian Philosophy (1858–59) and Studies in the Problems of Practical Philosophy (1860). Described as a quintessential Narodnik and a veteran of revolutionary theory Lavrov was involved in anti-government activities leading to arrest and sentencing to internal banishment. He fled to Paris, arriving in time to participate in the Paris Commune of 1871. Lavrov is known to have modified his theory after meeting Marx in London and then edited a number of the various publications of the Narodnaya Volya (“People’s Will”).