In Timeus** (approx. lines 50-53), Plato, writing in the voice of Socrates (or So-crates, for all my Bill & Ted buddies out there) turns his questions toward the nature of space. Plato believes that, so long as you have a conceptual starting point, you can discover new information about anything. His foundation comes at [50b-c] where Plato defines all that exists as:
(i) that which comes to be,
(ii) that in which it comes to be, and
(iii) that after which the thing coming to be is modeled, and which is its source.
The first one (i), “that which comes to be,” is matter. This is the stuff we and our senses interact with everyday. Things like the chair I’m sitting on and these pretzels I’m eating – and boy are they making me thirsty. The second (ii), “that in which it comes to be,” is space. It’s everything between that matter we are so familiar with. As Plato says, “Everything that exists must of necessity be somewhere, in some place and occupying some space” [52b]. The third (iii) is the infamous realm of Platonic forms. Forms are Plato’s conceptual ideal of all that is. A perfect equilateral pyramid may never be built by clumsy human hands, but we have the ideal concept of what it what it would look like. We can conceive of it through pure thought. Forms are a whole other blog series (or book).
Plato is fully aware of the complexity surrounding a definition of space. He sees it as something we look at as in a dream. He starts by developing three questions to guide his way. The first is, “what is space?” Is it material as in a container that holds all things or is it some kind of strange immaterial structure? Plato speaks of space as acquiring properties similar to matter. It is available for elements to make their impression upon while never taking on any characteristic of the objects which enter it. Like stamped clay, it can carry copies of objects without absorbing their traits. For Plato space seems to actually be material – “pure matter.” But, still far from being certain, he calls it “a thing extremely difficult to comprehend” [51b].
Plato’s second question is how can we come to find out anything about this invisible, elusive, yet all pervading thing? If space is something that cannot be learned about via pure reason (as the forms can) or empirical evidence (physical object), but can only be apprehended by a sort of intuitive “bastard reasoning” [52b], how can we hope to find anything out about it? How can we test our theories about it?
Plato’s last question involves the interaction of space and material objects. He wants to know how matter and space (also matter for Plato) interact with one another. It is obvious that objects lie in space, but what else does the relationship entail? Plato reasons that space and the elements all react with one another and affect each other.
You can see that even though he lived two and a half thousand years ago, Plato managed to set the stage for modern physics. He did so by dividing the concept of space into the three elemental questions above: the metaphysical which asks what kind of a thing is space; the epistemological, how can we come to know anything about space; and the physical, how do space and matter interact? All three of these must be explored to discover anything about the relation of place, motion, inertia, and the correlation between space and matter. Natural philosophers! Crack your knuckles and fire up your neural transmitters! I think we just boarded the Wonka boat. It’s gonna be a weird ride!
**The translation is from Readings in Ancient Greek Philosophy (pp. 463-466), Plato, “Timaeus,” translated by M.L. Gill and P. Ryan and published by Hackett in 1995.
If I Only Had A Brain... 