George Henry Lewes 
A Biographical History of Philosophy (Barnes & Noble Digital Library) [EPUB ebook] 
From Thales to Comte

This 1867 survey of philosophy is enlivened by portraits and discussions of Thales, Pythagoras, Socrates, Plato, Aristotle, and Euclid, through more modern philosophers such as David Hume and Immanuel Kant, ending with Auguste Comte. Sections focus on topics, such as the nature of the universe and the origin of knowledge, and groups, such as the Sophists and the Cynics.

Sobre el autor

George Henry Lewes (1817-1878) was an English philosopher, critic, and novelist.  Though married, he conducted a long-term affair with the writer George Eliot; the two considered themselves to be husband and wife.  His best-known works are
The Spanish Drama (1846),
Life of Goethe (1855), and
Problems of Life and Mind (1875-1879)
.