18 February 2008

Flux and Compresence

I've been looking at T. Irwin's interpretation of Plato on the Compresence of Opposites. You will recall that this was recommended as a philosophically more sophisticated view than, for instance, the simple and perhaps simplistic idea that Plato believed that all things were infested with contraries because all things were changing.

The simple and simplistic idea is expressed in the following argument:

1. Each thing, in any respect in which it is perceptible, is changing.
2. Anything which changes, in the respect in which it changes, has compresent opposite properties.
3. Thus, each thing, in any respect in which it is perceptible, has compresent opposite properties.
According to this argument, Flux implies Compresence, because change requires that the changing thing somehow partake simultaneously both of the terminus a quo and the terminus ad quem of the change. (Note: on this view, change in the true sense is not a mere succession of qualities, e.g. a thing changes if at time T1 it is F and at some later time T2 it is not-F.)

Now here's a curiosity about Irwin's interpretation. As we saw, he re-interprets Compresence in a very broad way, and as being about properties rather than particulars. For Irwin, Compresence becomes, in effect, the view that each property is such that there is at least one other property for which it is not a sufficient condition; i.e. for each property there is at least one other property that fails to be fixed when the former is fixed. Thus on this view circularity has opposites 'present in it', because to say that something is circular is to imply nothing about whether it is (say) green or not-green. So (Irwin would have it), both green and not-green are present in circularity.

Yet, at the same time, Irwin acknowledges that Plato is committed to a Doctrine of Flux. Below I give the relevant passages from Plato's Ethics below (from pages 161-2).

Now, when you read these passages, ask yourself: How can Irwin acknowledge all of these things, and yet still give such a weak reading of Compresence? If Flux implies Compresence of Opposites, in the sense of the simultaneous presence of contrary or contradictory properties in particulars, how can Irwin consistently affirm Flux but deny Compresence in that sense? Or is Irwin committed to two different accounts of Compresence, the sophisticated and the simple?

I'll give you my take on this in a later post.
...Plato himself speaks of change in sensibles and seems to regard this as a reason for denying that they can be objects of knowledge and definition. In the Cratylus he suggests that knowledge requires the existence of unchanging forms as objects of knowledge; even if sensibles are all in flux, forms must be exempt from flux (Cra. 439c6-440d2). In this passage Plato does not actually affirm that sensibles are in flux, but in other dialogues he seems to affirm precisely that; after he has argued that the Forms are different from sensibles, he claims that sensibles undergo constant change, whereas Forms are completely unchanging (Phd. 78c10-e4; R. 495a10-b3, 508d4-9, 518e8-9, 525b5-6, 534a2-3). ...

[Plato] explains who Protagoras' belief in the truth of appearances leads to the doctrine that 'nothing is any one thing itself by itself', because, for instance, you cannot call anything large without its appearing small,or heavy without its appearing light (Tht. 152d2-6). These appearances of compresence are the result of motion, change, and mingling, so that everything merely comes to be (hard, soft, light, heavy, and so on) and nothing stably is what we take it to be (152d2-e1).


Anonymous said...

Irwin p162 (re Tht 152d-e): "[Plato] therefore assumes that it is appropriate to speak of 'flux', 'change', and 'becoming' in describing the instability that is manifested in the compresence of opposites." Further below, summing up his discussion of this and some other passages from some other dialogues, Irwin concludes: "We ought not to assume, then, that when Plato speaks of flux he must have succession in mind; and so we ought not to be surprised when he begins by speaking of compresence and continues by speaking of change. We need not infer that Plato really intends some argument about succession or that he illegitimately infers succession from compresence; we should simply suppose that he assumes a broad interpretation of flux. The fact that he speaks of flux does not by itself tell us whether he has in mind change over time, compresence of opposites, or both at once. If we see that his arguments appeal only to compresence, not to change over time, we are justified in concluding that the type of flux he attributes to sensibles in explaining why they are unknowable is compresence."

See too Irwin's 1977 ("Plato's Heracleiteanism"), where the idea that, in Plato, "flux," "change," "becoming," etc. are not literally change. (So too e.g. GEL Owen in A Proof in the Peri Ideon.)

So, when Irwin "acknowledges that Plato is committed to a Doctrine of Flux," he is NOT thereby acknowledging that Plato is committed to the doctrine that sensible things are always (literally) *changing*.

Michael Pakaluk said...

Well, yes, that's correct as a report about what Irwin says. He maintains that all of Plato's talk about flux boils down to talk about compresence. But why? On what grounds (do you think) does Irwin assert this? (And are they good grounds?)

Also, if one were to grant that Plato's talk of flux does boil down to talk about compresence, is this at all plausibly compresence of properties, in the sense explained in sections 108-109 of the book(and which I have already described in earlier post)?

Prima facie one would think not, because flux is flux of particulars; and therefore the corresponding doctrine of compresence, to which it boiled down, would be compresence of opposites in particulars.


Anonymous said...

[anon again]

I think Irwin asserts that [a] flux boils down to compresence on the grounds that [b] this is what the considerations introduced to support flux suggest. (I think [b] is plausible in itself and reasonable grounds for [a].)

That said I don't think it at all plausible that compresence is compresence of properties, in the sense explained.

Michael Pakaluk said...

I agree that in a very general way it seems plausible to say that when Plato claimed Flux he was really interested in Compresence, but my concern is with how Irwin on his page 162 works this out. But more tomorrow.