 Whether unknowingly or deliberately , Simplicio , the defender of the Aristotelian geocentric view in Dialogue Concerning the Two Chief World Systems , was often caught in his own errors and sometimes came across as a fool . Indeed , although Galileo states in the preface of his book that the character is named after a famous Aristotelian philosopher ( Simplicius in Latin , " Simplicio " in Italian ) , the name " Simplicio " in Italian also has the connotation of " simpleton " . This portrayal of Simplicio made Dialogue Concerning the Two Chief World Systems appear as an advocacy book : an attack on Aristotelian geocentrism and defence of the Copernican theory . Unfortunately for his relationship with the Pope , Galileo put the words of Urban VIII into the mouth of Simplicio . 
