"If men define situations as real, they are real in their consequences." Thomas theorem is a theory of sociology which was formulated in 1928 by William Isaac

"If men define situations as real, they are real in their consequences." Thomas theorem is a theory of sociology which was formulated in 1928 by William Isaac Thomas and Dorothy Swaine Thomas. https://en.wikipedia.org/wiki/Thomas_theorem https://en.wikipedia.org/wiki/Thomas_theorem