Ever since he made his first portraits and self-portraits at the age of sixteen, David Hockney has been fascinated by people--"the human clay," as W. H. Auden put it--and how they have been represented throughout the history of art. As much as any other artist in recent years, he has embraced, invigorated, and often subverted traditional portraiture, making it a central concern of his work. Through a careful selection of works both iconic...