As The Principles of Psychology appeared a little over one hundred years ago, in 1890, this seems an appropriate time to review what is probably the best-known book in the literature of psychology.

William James was born in New York in 1842. His brother, the novelist Henry, was bom in the same city fourteen months later. Their parents were second-generation Americans, their father Henry being a wealthy amateur philosopher who espoused the views of Swedenborg. His father, who came from Ireland, had three wives and thirteen children and amassed a fortune, giving his grandsons leisure and confidence to make good use of their exceptional literary gifts and psychological insights. It has been said that Henry wrote like a psychologist and William like a novelist. However this may be, William James was the first important American psychologist; with the beauty and verve of his writing over a brave range of enquiry, he graced the subject indelibly and remains significant today.