Isaac Asimov was an American writer and professor of biochemistry, best known for his science fiction works and for his popular science books. He is widely considered to be one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90, 000 letters and postcards. Asimov is best known for his Foundation Trilogy, a series of science fiction novels which explore the concept of psychohistory.