Historian of psychology Mark Altschule observes that , `` It is difficult -- or perhaps impossible -- to find a nineteenth-century psychologist or psychiatrist who did not recognize unconscious cerebration as not only real but of the highest importance . ''
Historian of psychology Mark Altschule concluded , `` It is difficult -- or perhaps impossible -- to find a nineteenth-century psychologist or psychiatrist who did not recognize unconscious thought as not only real but of the highest importance '' .