Robert Brumbaugh a philosophy professor at the University of Yale that died in 1992 that was a decoder in US Army Signal Corps during World War II.
He attempted to decode Plato Critias
Book VIII of the Republic Plato consider the five type of leader in descending order of desirability:
These character types are product of the three parts of the soul:
- spirit and
combined with the four ascending levels of understanding described in books V-VII :
- conjecture ,
- understanding and
- reason .