Timaeus is one of Plato's dialogues, mostly in the form of long monologues given by Critias and Timaeus, written c. 360 BC. The work puts forward reasoning on the possible nature of the physical world and human beings and is followed by the dialogue Critias. Participants in the dialogue include Socrates, Timaeus, Hermocrates, and Critias. Some scholars believe that it is not the Critias of the Thirty Tyrants who appears in this dialogue, but his grandfather, who is also named Critias. It has been suggested from some traditions (Diogenes Laertius (VIII 85) from Hermippus of Smyrna (3rd century BC) and Timon of Phlius (c. 320 - c. 235 BC)) that Timaeus was influenced by a book about Pythagoras, written by Philolaus, although this assertion is generally considered false.