William Isaac Thomas (1863-1947) was an American sociologist and educator. He was a pioneer in the scientific use of personal documents and in pointing to the interplay between personality and culture.

On Aug. 13, 1863, W. I. Thomas was born in Russell County, Va. He majored in literature and languages at the University of Tennessee, where in 1886 he received the first doctoral degree granted by that institution. After a brief teaching stint in natural history and Greek at the University of Tennessee, he developed an interest in anthropology and sociology at the universities of Göttingen and Berlin. However, he returned to teaching at Oberlin College and then began advanced work in sociology at the University of Chicago.

From 1894 to 1918 Thomas was with the department of sociology at the University of Chicago, having received his second doctorate there in 1896. With the support of the Helen Culver Fund for Race...