The cosmology of Timaeus begins by distinguishing between "that which always is" and "that which comes to be." The visible, tangible universe is said to have come into being and possesses a cause.

Then, what did the creator of the universe use as a model? Timaios believes that the beautiful universe is an "image" reflecting something eternal. He also argues that when speaking about the created universe, one should strive for language appropriate to an image, rather than mathematical perfection.

Dialogue Text

Timaios (Continued) In my opinion, we must first distinguish between what always exists and has no origin, and what is constantly being generated but never truly exists. The former can be grasped through understanding that involves reasoning, and it maintains the same state at all times. The latter is only conceived of through sensory perceptions and illogical assumptions, and while it may appear to generate and perish, it never truly exists.

Timaios (Continued) Furthermore, everything that is generated is necessarily caused by something. It is impossible for anything to be generated without a cause.

Timaios (Continued). Therefore, if the creator contemplates something that always maintains the same form and uses such a pattern to create the shape and power of something, then what is produced will inevitably be beautiful and complete. However, if one uses what has been created as a pattern, it will not be beautiful.

Timaios (Continued). Now, concerning the entire cosmos – let us call it “the world,” or whatever name seems most appropriate – we must first consider what should be considered initially about everything. That is, whether the universe has always existed and had no beginning, or whether it began from some point in time and came into being.

Timaios (Continued) The universe was created because of what is visible, tangible, and possesses a body. And everything that exists is perceived. What is perceived is grasped through perceptions accompanied by thoughts, and it becomes clear that it is something that has been generated and made. Furthermore, we say that whatever is generated must have some cause for its generation.

Timaios (Continued) It is difficult to find the creator and father of this universe, and even if one finds him, it is impossible to tell everything about him to everyone. Nevertheless, we must once again consider in what direction the creator fashioned the universe: whether towards a constant form or towards that which is generated.

Timaios (Continued) If this world is beautiful, and its creator is good, then it is clear that the creator was contemplating something eternal. Otherwise, it would not be permissible to speak of it. It is obvious to everyone that the creator was looking at something eternal. The most beautiful thing among all things created is this world, and the best cause is the creator.

Timaios (Continued): Thus, since this world was created with the aim of grasping things through discourse and intellect, and maintaining a constant state, it must be an imitation of such things. Above all else, it is important to begin from the beginning, following nature. Therefore, we must distinguish between the imitation and its archetype, as follows: Discourse is related to what it describes.

Timaios (Continued): A discourse about things that are stable, firm, and become clear along with intelligence must be as stable, unchanging, unrefuted, and unwavering as possible. In contrast, a discourse about generated things, which are likenesses of those eternal things, must be a discourse appropriate to the likeness and fitting for what is generated. If there exists being in relation to generation, then there exists truth in relation to belief.

Timaios (Continued). Therefore, Socrates, do not be surprised if we cannot speak with perfect precision and without contradiction in every respect about the generation of the gods and the entire cosmos. If someone can offer a statement that is worthy of being considered an approximation, we should accept it and rejoice, because both I who am speaking and you jurors are human beings. Therefore, if you have accepted a story that is worthy of being considered an approximation regarding these matters, there is no need to seek anything more.