A stern parent, James Mill taught his son Greek at the age of three, and at seven he studied Plato's dialogues. When he was eight he had to teach his sister Latin. His introduction to the utilitarian teachings of Bentham (the greatest happiness to the greatest number) at the age of fifteen was decisive for his life. His great work, System of Logic, 1843, is the analysis of inductive proof. He was a great champion of human rights, and in the second half of the 19th century his influence throughout Europe was very great. Today it is recognized that, to use Mill's description of Bentham, "He was not a great philosopher but a great reformer in philosophy."