Frank Baxter
Himself (as Dr. Frank C. Baxter)
?
Hadley Cantrell
Himself - Princeton University Psychologist (as Professor Hadley Cantrell)
Edwin Max
Bill
?
Wilder Penfield
Himself - Director: Montreal Neurological Institute (as Dr. Wilder Penfield)
Peter Brown
Aristotle's student (uncredited)
Karl Swenson
Hal - the Cameraman (uncredited)