Timaeus is one of Plato's dialogues, mostly in the form of a long monologue given by the titular character, written circa 360 BC. The work puts forward speculation on the nature of the physical world and human beings. It is followed by the dialogue Critias. Speakers of the dialogue are Socrates, Timaeus of Locri, Hermocrates, and Critias. Some scholars believe that it is not the Critias of the Thirty Tyrants who is appearing in this dialogue, but his grandfather, who is also named Critias.