William Thetford was an American psychologist and educator, best known for his work in the field of psychology and his collaboration with Helen Schucman. Together, they co-authored the influential spiritual text, A Course in Miracles, which emphasizes the principles of forgiveness and inner peace. Thetford served as a professor at Columbia University and was deeply involved in the study of human consciousness. His contributions to psychology and spirituality have had a lasting impact, inspiring many individuals to explore their inner selves and seek personal transformation through the teachings found in A Course in Miracles.