William Isaac Thomas

William Isaac Thomas (August 13, 1863 – December 5, 1947) was an American sociologist, understood today as a key figure behind the theory of symbolic interactionism.

Collaborating with Polish sociologist Florian Znaniecki, Thomas developed and influenced the use of empirical methodologies in sociological research and contributed theories to the sociology of migration. Thomas went on to formulate a fundamental principle of sociology, known as the Thomas theorem, whereby he would contend that "if men define situations as real, they are real in their consequences." This microsociological concept served as a theoretical foundation for the field of symbolic interactionism which was developed by Thomas's younger peers—primarily at the University of Chicago.

Personal life

William Isaac Thomas was born on a farm in the Elk Garden section of Russell County, Virginia, on 13 August 1863. His mother was Sarah Price Thomas and his father was Thaddeus Peter Thomas, a Methodist minister of Pennsylvania Dutch descent. Thomas' father, wanting to broaden the educational opportunities for his children, moved the family to Knoxville, home of the University of Tennessee, when Thomas was a boy.

In 1888, Thomas married his first of two wives, Harriet Park, and in 1935, after the two divorced, Thomas married Dorothy Swaine Thomas, 36 years his junior. Dorothy worked as his research assistant and co-author and would become the first woman president of the American Sociological Association in 1952 (William had been president in 1927).