He was professor of philosophy in the university of Toronto (1889), of psychology at Princeton (1893), and subsequently (1903) of philosophy and psychology in Johns Hopkins University.
Prominent among experimental psychologists, he was one of the founders of the Psychological Review.
In 1892 he was vice-president of the litternational Congress of Psychology held in London, and in 1897—1898 president of the American Psychological Association; he received a gold medal from the Royal Academy of Arts and Sciences of Denmark (1897), was honorary president of the International Congress of Criminal Anthropology held in Geneva in 1896, and was made an honorary D.Sc. of Oxford University.
Apart from articles in the Psychological Review, he has written: