The Timaeus begins with Socrates’ desire to see the city he creates in the Republic at war. He wants to see the city in action. The story of the city in the Republic is incomplete. It is a city created by intellect without necessity, that is, a city without chance and contingency. A city that could never be.

The fixed intelligible world, the world of Forms, is not the whole of the story. The Forms are part of a whole that is indeterminate, a whole in which there is contingency and chance. Sensible things are not as they are simply because they are likenesses of Forms. They are as they are because of the random actions they are involved with in the chora. By being shaken the chora both acts on and is acted on by what is in it.


Timaeus introduces the divine craftsman he calls “poet and father'' of all that comes to be. (28c [correction])

He does not attempt to demonstrate or prove or defend the existence of the craftsman. We are led to ask how Timaeus knows of him. The suspicion is that Timaeus is the craftsman, the poet and father, of the divine craftsman.

It is one of the many likely stories (ton eikota mython) he tells:

So then, Socrates, if, in saying many things on many topics concerning gods and the birth of the all, we prove to be incapable of rendering speeches that are always and in all respects in agreement with themselves and drawn with precision, don’t be surprised. But if we provide likelihoods inferior to none, we should be well-pleased with them, remembering that I who speak as well as you my judges have a human nature, so that it’s fitting for us to be receptive to the likely story about these things and not search further for anything beyond it. (29c-d).

His imprecision is seen here as well:

As for all the heaven (or cosmos, or whatever else it might be most receptive to being called, let us call it that) … (28b).

Why not be more precise? Isn’t it imperative to be precise in matters of metaphysics and cosmogony?

We are human beings, capable of telling likely stories, but incapable of discerning the truth of such things. In line with the dialogues theme of what is best, Timaeus proposes it is best to accept likely stories and not search for what is beyond the limits of our understanding.

Socrates approves and urges him to perform the song (nomos). Nomos means not only song but law and custom or convention. In the absence of truth there is nomos. But not just any song, it is one that is regarded as best to accept because it is told with an eye to what is best. One that harmonizes being and becoming.
Timaeus identifies two kinds of cause, intelligence and necessity, nous and ananke. Necessity covers such things as physical processes, contingency, chance, motion, power, and the chora. What is by necessity is without nous or intellect. It is called the “wandering cause” (48a). It can act contrary to nous. The sensible world, the world of becoming, is neither regulated by intellect nor fully intelligible.

In addition to Forms and sensible things, Timaeus introduces a “third kind” (triton genos, 48e), the chora (χώρα).

The three kinds are:

… that which comes to be, that in which it comes to be, and that from which what comes to be sprouts as something copied. And what’s more, it’s fitting to liken the receiver to a mother , the ‘from which’ to a father, and the nature between these to an offspring (50d).

Like intelligible things, the chora always is. But unlike intelligible things, it is changeable. (52a) Unlike sensible things it does not perish. Befitting its indeterminacy, the chora does not yield to simple definition.

It is said to be the seat of all that has birth. (52b)

He calls it:

… a receptacle for all becoming, a sort of wet nurse.

The chora does not take the shape of anything it receives but is:

… both moved and thoroughly configured by whatever things come into it; and because of these, it appears different at different times ... (50c)

And because she is filled with powers neither similar nor equally balanced, but rather as she sways irregularly in every direction, she herself is shaken by those kinds and, being moved, are always swept along this way and that and are dispersed - just like the particles shaken and winnowed out by sieves and other instruments used for purifying grain … ( 52e)

The chora is not itself active, but due to what is active within it, it moves and thus contributes to the movement of what is in it. Like a sieve, it is not active but by being acted on it acts on what is in it.

The chora, to the extent it is understood, is grasped by:

… some bastard reasoning with the aid of insensibility, hardly to be trusted, the very thing we look to when we dream and affirm that it’s somehow necessary for everything that is to be in some region [topos] and occupy some space [chora] and that what is neither on earth nor somewhere in heaven is nothing (52b-c).

To be clear, it is not that the chora is posited as the result of bastard reasoning. It is the attempt to understand it that relies on bastard reasoning. We cannot understand the chora itself. We rely on images of space and place. In dreams we mistake images for their originals (Republic 476c), but the chora is not some thing with its own properties and identity. Reasoning about it cannot make use of the image/original distinction. It is indeterminate and something thought of only in terms of images.
The image of chora as mother and the father as that “from which” the offspring come raises the problem of paternity. Both the divine craftsman and the Forms have been identified as the father of what comes to be.

In this likely story the offspring are the sensible beings. Any inquiry into the beginning cannot start at the beginning. Timaeus’ likely story, like all such stories, is not to be trusted. It is imprecise and contradictory, just as he said it would be. It is the work of a human craftsman . The beginning remains inaccessible to us. Perhaps what Plato is suggesting is that the offspring of origin stories, including those found in Plato’s dialogues, are the result of bastard reasoning and illegitimate.

A central concern for Timaeus is the beginning of all things (48c):

But by safeguarding what we declared at the very beginning - the power of likely accounts - I’ll attempt to give an account not less likely but more so and to speak, as before from the beginning about things individually and together as a whole. (48d)

Timaeus begins with a likely account of the beginning, which is to say, not at the beginning, but with where he is able to begin. The inability to identify the true father, the origin, the beginning, leads to bastard reasoning. Our reasoning is on the basis of likeness in the double sense of sensible things being a likeness without ever having what belongs to that which it is a likeness of (52c) and, a likeness in the sense of being likely or like what it is without being what it is that it is like. And, of course, without access to the original we cannot say just how likely the story is to be true.

In a dream we fail to distinguish between things and images. We should not mistake our images of the chora for the chora itself. It is not something sensed but it is not an intelligible either. It is a third kind, one that cannot be fully explicated. One that points to the mystery and indeterminacy of what is at play in the world.

The image of the city at war is an image of a place or space, a chora, in which there is both intelligible order and chance, harmony and disharmony. Where things stand both together and in opposition.

Forms and Chora are an indeterminate dyad. Together they order all that comes to be through intellect and necessity, that is, according to paradigm and chance, order and disorder, determinacy and indeterminacy.

For more on the indeterminate dyad: https://thephilosophyforum.com/discussion/11903/platos-metaphysics/p1