Antonio Labriola (July 2, 1843 - February 12, 1904) was an Italian Marxist theoretician. Although an academic philosopher and never an active member of any political party, his thought exerted influence on many political theorists in Italy during the early 20th century, including the founder of the Italian Liberal Party Benedetto Croce and the founder of the Italian Communist Party Antonio Gramsci.
Labriola was born in Cassino (then in the Papal States), the son a schoolteacher. In 1861, he entered the University of Naples. Upon graduating, he remained in Naples and became a schoolteacher. During this period, he pursued an interest in philosophy, history and ethnography. The early 1870s saw Labriola take up journalism and his writings from this time express liberal and anticlerical views.
In 1874, Labriola was appointed as a professor in Rome, where he was to spend the rest of his life teaching, writing and debating. Although he had been critical of liberalism since 1873, his move towards Marxism was gradual, and he did not explicitly express a socialist viewpoint until 1889.
Heavily influenced by Georg Wilhelm Friedrich Hegel and Johann Friedrich Herbart, Labriola's approach to Marxist theory was more open-ended than the orthodoxy of theorists such as Karl Kautsky. He saw Marxism not as a final, self-sufficient schematisation of history, but rather as a collection of pointers to the understanding of human affairs.
It was necessary that these pointers be somewhat imprecise if Marxism was to take into account the complicated social processes and variety of forces at work in history. Marxism was to be understood as a "critical theory", in the sense that it sees no truths as everlasting, and was ready to drop its own ideas if experience should so dictate. His description of Marxism as a "philosophy of praxis" would appear again in Gramsci's Prison Notebooks.