Plato's Parmenides III: Greater Difficulties

Parmenides now moves on to raise two stern objections to Socrates' theory of Forms. Edith Hamilton's translation has a very brief introduction to the dialogue in which she says that it is unclear why Plato wrote a dialogue that was so harshly critical of his own most cherished idea. It is "certainly a curious procedure since in the end he apparently neither demolishes them nor establishes them," she says, but "[t]o some people, however, it is only what is to be expected from Plato, never out to defend his own views, always with one object alone, to know the truth. It would be natrual for him to do his best to find out if what he had built up could be torn down."

Especially the second of these two objections will remain relevant in theology even to this day: in the Middle Ages, Maimonides and others were gravely concerned with the proof that God could not know us. 

Parmenides sets up his first objection with a reprise of his Third Man argument. If these Forms exist like ideas in a mind, then they are unlike the things in the world. The things in the world that are supposed to be 'made in their image' have extension in three dimensions, weight, color, and so forth; the forms are unextended objects, which cannot have parts (as per the last discussion). Thus, no Form is anything like the things for which it is supposed to be the model. 

A further proof that the Forms cannot be 'like' the things in the world is that, if they were, then there is room for a third concept that unifies the Form and the thing it is 'like.' You have the Form of a Table, say, and a bunch of actual tables; what holds those things together as a category? If the Form of a Table is an idea about the essential nature of a table, then it is the thing that holds all the tables together in a category. Yet if the Form of a Table is like the tables in some way, then another idea must exist that holds the Form together with the several tables. (The real objection is not that there must be a 'third' thing, but that the process will repeat infinitely, so that knowing any Form requires knowing an infinite number of higher Forms as well).

Now he gets to what he calls his "worst" objection to the Theory of Forms. If the Forms are supposed to be ideas that capture the real essence of a thing, then knowledge of them should be knowledge of the real things. Yet knowing a Form gives you no knowledge about the facts of the world. His (unfortunate) example is slavery: knowing the Form of Master and the Form of Slave doesn't tell you who is a slave; and even if you recognize a slave, it doesn't tell you who his master is. "The significance of things in our world is not with reference to things in that other world [i.e. the world of the Forms]." 

If that is true, the real and best kind of knowledge will be knowledge of a world so separate from ours that knowing the truth would provide us with no benefits. Our branches of knowledge, insofar as they exist in this world, would seem to involve knowledge of the real things -- not knowledge of the ideal things. 

This leads to the second objection, which is the one that bothered theologians. It would seem that "a god," and certainly God, would have the best kind of knowledge. Indeed, the usual way of talking about the Forms since the advent of Christianity is to talk about them as "Ideas in the Mind of God." So God, at least, knows the forms even if none of us do.

But because God knows the Forms, what God knows is not knowledge of this world but of the world of Forms. Later monotheistic theologians will prove to their satisfaction that God himself must be simple and unextended -- this is Aquinas' position, and Avicenna's, and Maimonides' -- and thus the Forms are the only things God could know, because they are simple and lack parts too. 

Even in Parmenides' day, the perfection of divine knowledge implied knowledge of the Forms rather than knowledge of particulars. 
Then if the most perfect mastership and most perfect knowledge are in the god's world, the gods' mastership can never be exercised over us, nor their knowledge know us or anything in our world. Just as we do not rule over them by virtue of rule as it exists in our world, and we know nothing that is divine by our knowledge, so they, on the same principle, being gods, are not our masters nor do they know anything of human concerns.
This is an intolerable objection in the eyes of the Christian philosophers especially, for whom a personal relationship with God is the essence of the faith. Yet it's also a problem for Jewish philosophers, for whom their foundational books are all about God knowing particular prophets and others, and working with them directly. 

(The Muslim philosophers seem unbothered by it; this would explain, e.g., why Allah communicated to Muhammad through an angel rather than directly. The angels serve a metaphysical role as messengers and intermediaries between the divine and the human. Avicenna's proofs of divine simplicity are thus thoroughgoing and unbothered by the fact that the consequence is that humans cannot have a direct relationship with such a God as he describes.)

Aristotle accepts these objections, and generally rejects separate Forms (with the exception of Unmoved Movers, as mentioned, whose role for him doesn't require them to know us). He has a totally different idea about how knowledge of the forms works. If you're interested, and you have a little more than an hour, here is the best philosopher working today on this subject explaining how he believes Aristotle's model works.


Plato's model is that the Forms do exist separately, in spite of these problems that Parmenides raises. We still have a lot of ground to cover, but at least now you understand some of the problems that Plato expects to have to overcome in order to maintain his position.

7 comments:

Tom said...

This is interesting, but I tend to think the "Forms" are linguistic and cognitive, so I don't have much to say about it at the moment.

Grim said...

So, that's the 'psychological' rather than 'metaphysical' idea of Forms; but it is, I think, inadequate. Form actually does something that is real, and it's not too hard to say some things about it.

Consider the case we were discussing with James a while ago: water's wetness emerging from hydrogen and oxygen. If you've got three atoms, two H and one O, that are separate from each other, they're not wet. You can (James tells us) do some good math on their properties that will predict something about wetness if they were to get together; but they're not wet.

Put them in the right organization, the right 'form' so to speak, and wetness emerges as a new property. That's not merely conceptual nor merely psychological; it's a physical fact.

Now, all the same material was there before and after they joined. What's changed is the order, the organization, the shape of assembly -- the form, in a word.

That's roughly Aristotle's idea of form, rather than Plato's. Consider a bed, except instead of being assembled it's all in a heap on the floor. All the same matter is there, but to be functional as a bed, you need to put it in the right form. What form? Well, the form of a bed! This form must be immaterial, since the material doesn't change; the same matter is there before and after assembly. Thus, when you put the matter in the right form, you get new functions that you didn't have before.

Aristotle's got something very different going on, of course, and you may just like his approach a lot better. Many people find it more plausible. Yet even for Aristotle, form isn't just an idea; it's very often a real physical fact (but physical without being, interestingly, material).

Grim said...

A related mystery:

https://www.wired.com/story/physicists-chip-away-at-a-mystery-why-does-glass-exist/

james said...

I'm not understanding something.

The Form of Tables does not seem to have clear differences from the Form of Stools--except in their respective purposes. Those purposes vary with the circumstances of the instance: when I'm on the floor picking up the broken plate the stool serves as a table for me. So it would seem that knowledge of the Form would include knowledge of the circumstances of instances, real or possible. I suppose you can subdivide Tables into Tables with X and Tables with Y circumstances, but wouldn't that subdivision eventually converge to the real instance at hand?

Would God would have "the best kind of knowledge" or _all_ kinds of knowledge (of what is and what could be)? Or more clearly, what does "best" mean? Is the best vector one that points a distance 1 along the x axis, or one that points a distance 1 along the y axis? Some things aren't ordered.

Grim said...

The Form of Tables does not seem to have clear differences from the Form of Stools--except in their respective purposes.

Yes, function is a very important part of this from the ancient perspective. It's telos: the end for which the thing came to be, its reason for existence. Artifacts like tables and chairs aren't the interesting cases, they're just easy to explain because they have a clear telos that we (post?) Moderns can admit actually exists. We know why we built the stool, and why we built the table, and what they're each supposed to do (even if we sometimes use them for other things).

Would God would have "the best kind of knowledge" or _all_ kinds of knowledge (of what is and what could be)? Or more clearly, what does "best" mean?

Parmenides means something different from the Medievals, although his problem gets wrapped up in their problem because Avicenna successfully melds Neoplatonic thought with Aristotelian thought. For Parmenides, knowledge of the Forms is better because it is the true knowledge: not just knowledge of a person, or a bunch of people, but a true understanding of what Men are and why they exist. Yet in grasping this exalted knowledge, you end up missing the individual men -- none of whom may fully achieve the purpose of Men, all of whom have potentials they don't realize, etc. Knowing the Form doesn't imply knowing any of the individuals who participate in the Form.

The Medievals have an additional problem. Aristotle proves that the Unmoved Movers (which they take for God) is a pure activity. God lacks unrealized potential, being perfect; and, therefore, God's knowledge is unchanging (because things can only change if they have the potential to be something else). Now knowing the Forms is fine, because the Forms are pure activities too: form is what causes matter's potential to be realized in one particular way. But to know a material object means knowing not just its Form, but its matter -- and that is incompatible with the idea of God as pure activity.

Maimonides (The Guide for the Perplexed, Part III, Chapter 20) explains his solution this way: God knows only Himself, but in knowing Himself God knows what He has willed, and all of the consequences of that. God's knowledge doesn't change because He knows the whole of time together, and without any potential because He can see how it all plays out. Thus, God can know particulars, in a way: God knows them as they will actualize.

That still seems to remove something important, which is the struggles we all have with actualizing ourselves (e.g., sin is the potential to do something worse than we might have done).

Aquinas treats this in ST I Q14 (especially article 5ff) and Q15 (on the Forms, which are called 'ideas' here).

james said...

I am a mere amateur at Church history and theology, but I have the distinct impression that there was a surge in interest in apophatic theology in the century after the great Christological debates. Reading Aquinas always reminds me of that. But those references help, thanks.

BTW, did you ever read "Place of the Lion" by Charles Williams?

Grim said...

Yes, that's right; all of these thinkers have a lot to say about negative theology. You can approach God by eliminating things that God is not, even though there's a problem saying anything much about what God is.

Even when you can say something positive -- "God is Good" -- there's a problem related to the problem of the Forms. What it means for God to be "good" is nothing like what it means for a material being like ourselves to be "good." The two words are (Aquinas' language) 'equivocal' rather than 'univocal.'

So the negative is a viable road, but unfortunately, it's a road that embraces all the positive qualities as well. God is not 'good' in the way that any of us are; God is Good in the way of the Form of the Good. What does that mean? Well, it's intelligible -- knowing the Form as well as we do is how we recognize that other things are 'good' in one way or another. Yet at the same time, we can't fully grasp it because of our own limits.

That's how the Medievals tell the story, anyway.

I haven't read the book you mention. It sounds worthy!