Calvin S. Hall Professions : Psychologist Born : 1909 Died : 1985 Browse All Authors Famous Quotes by Calvin S. Hall Effective thinking consists of being able to arrive at the truth; truth being defined as that which exists. Calvin S. Hall truth reality thinking Similar Authors Bruno Bettelheim psychologist Boris Sidis psychologist Anthony Greenwald psychologist Arnold Gesell psychologist Arno Gruen psychologist Anna Freud psychologist All Authors