Charles Hartshorne was the leading representative of process philosophy during the second half of the twentieth century; but his career spanned the better part of the century, and his influence extended beyond philosophy to theology, psychology, and ornithology. He traveled widely, and he knew or corresponded with many seminal figures in twentieth-century philosophy. His publications--including books, articles, and reviews in professional journals--number more than five hundred. The journal Process Studies, founded in 1971, is devoted in part to the study and critique of his work.

Hartshorne (the name, which means "deer's horn," is pronounced "hart's horn") was born on 5 June 1897 in Kittanning, Pennsylvania, to Francis Cope Hartshorne, an Episcopal minister, and Marguerite Haughton Hartshorne. He was named for a grandfather who had helped design a transcontinental railroad; the town of Hartshorne, Oklahoma, was named after the grandfather. He had one older sister, Frances, and four younger brothers: identical twins...