Simplify the following text for a Grade 16 native English-speaking person.
Original: Yet , as historian of psychology Mark Altschule concluded , `` It is difficultâ '' or perhaps impossibleâ '' to find a nineteenth-century psychologist or psychiatrist who did not recognize unconscious cerebration as not only real but of the highest importance . ''
Simplified: Historian of psychology Mark Altschule concluded , `` It is difficultâ '' or perhaps impossibleâ '' to find a nineteenth-century psychologist or psychiatrist who did not recognize unconscious thought as not only real but of the highest importance '' .