At the age of three he was taught Greek. By the age of eight he had read Aesop's Fables, Xenophon's Anabasis, and the whole of Herodotus, and was acquainted with Lucian, Diogenes Laërtius, Isocrates and six dialogues of Plato. He had also read a great deal of history in English and had been taught arithmetic, physics and astronomy.He continued his studies and at fourteen he spent a year in France. He met other intellectuals and became pen pals with Auguste Comte, the creator of sociology. When he was twenty he suffered a nervous breakdown, which he blamed on his rigorous studies. He recovered in time, in part through the poetry of Wordsworth.
At the age of eight he began studying Latin, the works of Euclid, and algebra, and was appointed schoolmaster to the younger children of the family. His main reading was still history, but he went through all the commonly taught Latin and Greek authors and by the age of ten could read Plato and Demosthenes with ease. His father also thought that it was important for Mill to study and compose poetry. One of Mill's earliest poetry compositions was a continuation of the Iliad. In his spare time, he also enjoyed reading about natural sciences and popular novels, such as Don Quixote and Robinson Crusoe.
Mill refused to go to either Oxford or Cambridge because he wouldn't subscirbe to the 39 Articles of the Church of England. Instead he attended lectures at University College in London.
When Mill was 45, he married a long term friend of his, Harriet Taylor. In part from association with her, he became an advocate of women's rights. He credited her with help as he was writing 'On Liberty'. He published it shortly after her death, seven years after they married.
Later in life, Mill served in Parliament and was the first person there to call for the right of women to vote. He was in favor of unions and farm co-ops. He was the godfather to Bertrand Russell(!).
Mill died in 1873 while living in Avignon. His last words were "You know that I have done my work."