In the Timaeus Plato narrates the formation of the universe by a divine Demiurge and fully develops a teleological world-picture.


In an important passage, the Socrates of the Phaedo relates how he devoted himself to studying nature when he was young, in line with the trend of the period, only to be eventually let down, since neither Anaxagoras nor any other natural philosopher provided him with an answer regarding the true cause applying throughout the universe, “with regard to the good (αγαθόν) and the proper (δέον) connecting and holding everything together” (99c). He justifies his flight to the Forms as a “second voyage in quest of the cause”, as an alternative and wiser course to “the truth of beings” (99e), a course that seems “simple and without skill, perhaps foolish”(100d).

This part of the text is presented as “autobiographical” by Socrates, yet it condenses Plato’s superb writing skills. The historical Socrates may very well had been disappointed by natural philosophy before he turned philosophy toward man. But it is doubtlessly Plato himself who introduced the Forms, and not as a “second voyage”, because his contempt for the world of the senses and its inherent causes is evident from his first writings and reaches its apex in the so-called middle period of his writing.

In his dialogues from this period, Plato holds that distancing oneself from the body, the senses and desires is a prerequisite for the ascent toward the Forms. Philosophy is defined as a “study of death” (μελέτη θανάτου) (Phaedo 81a), as complete devotion to the ascetic path of knowledge (Republic 539d-540b), which could “suddenly” (εξαίφνης) lead to the disclosure of the Forms (Symposium 210e). Indeed, Plato seems to have compromised with the view that true philosophy is ultimately aimed at a restricted intellectual elite, who has nothing to gain by studying the natural world.


 This picture changes radically in Plato’s later works. In the Timaeus Plato offers an impressively thorough analysis of the natural world. In the Philebus he claims that the good life is made up of a harmonious mixture of thought (φρόνησις) and pleasure. In the Laws ethical and political order is not assigned to the philosopher-king, but to the wise and foresighted lawgiver. Plato’s philosophy becomes less otherworldly and its potential audience is broadened.

Plato narrates in the Timaeus how a geometer-god created the world. The heavens are presented as a realm of perfection, because the only change featured therein is eternal and revolving movement, the infallible clock of time. Plato marshals the latest word of mathematical astronomy, in order to demonstrate that every movement of the heavens, even the complex movement of the planets, is actually circular and regular. In our world that lacks order and reason, therefore, there is a place where order reigns. If one were to consider human beings, which are presented as a faulty creation, as a miniature of the cosmos, one would discern that the realm of order corresponds to the immortal part of the soul, the place where intellect resides. At least potentially, everyone can develop this part of their soul and properly mobilise their intellectual powers. But, whereas Plato would previously claim that this can only be achieved through knowledge of the Forms, he now offers a more accessible way that makes use, moreover, of the deceptive human senses. If people were to turn their eyes toward the heavens and observe carefully, they would discover the regularity and periodicity of their movements, they would apprehend the concept of time. Yet time is the rhythmical movement of the universe and is interwoven with number; and numbers are, for the later Plato, the royal road to philosophy.

Philosophical knowledge, and its accompanying ευδαιμονία, is now more accessible -- indeed, more so for everyone. It takes place within the sensible world, not in some supersensible place; it does not seek the annihilation of the body and the senses, but only the mind’s training.

In the last period of his life Plato decides to turn to cosmology and physics and to establish a teleological world-picture, by actually overcoming his contempt for the phenomena, because he realises that by “ceding” this sphere to his rivals he fails to confront the devastating skepticism threatening the realm of ethical and political behaviour. Should one grant that the natural world is chaotic and irrational (and, according to Plato, this is Democritus’ universe, because it lacks design and purpose), then in what way, on what grounds, and how persuasively is one to defend the rationality of human action? Instead of saving a special group of people with exceptional features from universal chaos, in the hope that granting them power would ultimately bring order to the city, it is preferable to reverse the picture of nature. Mathematical astronomy plays a key role in this reversal restoring the order of the heavens. In a universe of order and reason, human behaviour that is unethical and lacks reason seems out of place as well as remediable.

vision of day and night and of months and circling years has created the art of number and has given us not only the notion of Time but also means of research into the nature of the Universe. From these we have procured Philosophy in all its range, than which no greater boon ever has come or will come, by divine bestowal, unto the race of mortals Timaeus 47a

the works and actions that are great and primary will be those of art, while so-called nature itself and what is attributed to it will be secondary and will derive their origin from art and reason. Laws 892b
Author: Vassilis Kalfas
  • Cornford, F.M. Plato’s Cosmology. Λονδίνο, 1937.
  • Johansen, T.K. Plato's Natural Philosophy. Καίμπριτζ, 2004.
  • Sedley, D. Creationism and its Critics in Antiquity. Μπέρκλεϋ, 2009.
  • Vlastos, G. Plato’s Universe. Οξφόρδη, 1975.


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