Antonyms for Robert Green Ingersoll may include religious, conservative, orthodox, close-minded, and traditional. Ingersoll was a prominent American orator of the late 19th century, famously known for his advocacy of reason, science, and freethought. His views on religious skepticism, individualism, and social justice were considered radical in his time. Opposite to Ingersoll's liberal outlook, his antonyms may signify a tendency towards dogmatism, conformity, and authority. Ingersoll's legacy as a freethinker and humanist continues to inspire the contemporary secular movement and the fight for civil liberties and equal rights.