"It seems natural to suppose... the Pythagorean elements of Plato’s Phaedo and Gorgias come mainly from Philolaos. Plato makes Sokrates express surprise that Simmias and Kebes had not learnt from him why it is unlawful for a man to take his [own] life, and it seems to be implied that the Pythagoreans at Thebes used the word "philosopher" in the... sense of... seeking to find... release from the burden of this life? It is... probable that Philolaos spoke of the body... as the tomb... of the soul. ...[H]e taught the old Pythagorean religious doctrine in some form, and... likely... laid stress upon knowledge as a means of release. ...Plato ...is by far the best authority ...on the subject."