 Although it is not certain, Posidonius may have written a commentary on Plato's "Timaeus".He was the first Stoic to depart from the orthodox doctrine that passions were faulty judgments and posit that Plato's view of the soul had been correct, namely that passions were inherent in human nature.In addition to the rational faculties, Posidonius taught that the human soul had faculties that were spirited (anger, desires for power, possessions, etc.)