Robert A. Harper, Ph.D. was a psychology and sociology professor, a psychiatric social worker in the U.S. Army, and prominent marriage and family counselor. He wrote several books with Albert Ellis, including Creative Marriage, A Guide to Successful Marriage, and A Guide to Rational Living, among others. His Psychoanalysis and Psychotherapy: 36 Systems was one of his most influential books. He lived and practiced in Washington, D.C., until his passing in 2004.