Timaeus (dialogue)

The work puts forward reasoning on the possible nature of the physical world and human beings and is followed by the dialogue Critias.

Critias believes that he is getting ahead of himself, and mentions that Timaeus will tell part of the account from the origin of the universe to man.

[citation needed] Timaeus describes the substance as a lack of homogeneity or balance, in which the four elements (earth, air, fire and water) were shapeless, mixed and in constant motion.

"Wherefore, using the language of probability, we may say that the world became a living creature truly endowed with soul and intelligence by the providence of God" (30a–b).

Additionally, because the demiurge wanted his creation to be a perfect imitation of the Eternal "One" (the source of all other emanations), there was no need to create more than one world.

The creator decided also to make the perceptible body of the universe by four elements, in order to render it proportioned.

Moreover, since the world is not a surface but a solid, a fourth mean was needed to reach harmony: therefore, the creator placed water and air between fire and earth.

The creator assigned then to the world a rotatory or circular movement, which is the "most appropriate to mind and intelligence" on account of its being the most uniform (34a).

Timaeus then explains how the soul of the world was created (Plato's following discussion is obscure, and almost certainly intended to be read in light of the Sophist).

[6] He then divided following precise mathematical proportions, cutting the compound lengthways, fixed the resulting two bands in their middle, like in the letter chi (Χ) and connected them at their ends, to have two crossing circles.

The world as a whole, the planets, and the stars are living, visible gods (39e) that have an important role in creating human beings and regulating their moral life (41d).

[7] Timaeus claims that the minute particle of each element had a special geometric shape: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth).

Timaeus makes conjectures on the composition of the four elements which some ancient Greeks thought constituted the physical universe: earth, water, air, and fire.

Particular characteristics of matter, such as water's capacity to extinguish fire, was then related to shape and size of the constituent triangles.

Cicero's fragmentary translation was highly influential in late antiquity, especially on Latin-speaking Church Fathers such as Saint Augustine who did not appear to have access to the original Greek dialogue.

[13] Calcidius' more extensive translation of the Timaeus had a strong influence on medieval Neoplatonic cosmology and was commented on particularly by 12th-century Christian philosophers of the Chartres School, such as Thierry of Chartres and William of Conches, who, interpreting it in the light of the Christian faith, understood the dialogue to refer to a creatio ex nihilo.

[17] During much of the Middle Ages in the Latin-speaking West the Timaeus was the sole work of Plato which was typically available in monastic libraries.