Plato's eight deduction, how to explain
Hi, I am from China and preparing my post-graduate entrance examination(philosophy), so when I was reading the Plato's eight deduction, these Chinese translations are very different, thus I turn to read SEP's interpretation, and I got these probloems.
(D1) If the G is, then the G is not F and not con-F in relation to itself.
(D2) If the G is, then the G is F and con-F in relation to the others.
(D3) If the G is, then the others are F and con-F in relation to the G.
(D4) If the G is, then the others are not F and not con-F in relation to themselves.
(D5) If the G is not, then the G is F and con-F in relation to the others.
(D6) If the G is not, then the G is not F and not con-F in relation to itself.
(D7) If the G is not, then the others are F and con-F in relation to the G.
(D8) If the G is not, then the others are not F and not con-F in relation to themselves.
What is G? And what is F?
Is G an idea? Is F a property?
And if F is a property, con-F is the contrary to F, how could I explain "G is not F and not con-F"?
Thanks for your time read this.
(D1) If the G is, then the G is not F and not con-F in relation to itself.
(D2) If the G is, then the G is F and con-F in relation to the others.
(D3) If the G is, then the others are F and con-F in relation to the G.
(D4) If the G is, then the others are not F and not con-F in relation to themselves.
(D5) If the G is not, then the G is F and con-F in relation to the others.
(D6) If the G is not, then the G is not F and not con-F in relation to itself.
(D7) If the G is not, then the others are F and con-F in relation to the G.
(D8) If the G is not, then the others are not F and not con-F in relation to themselves.
What is G? And what is F?
Is G an idea? Is F a property?
And if F is a property, con-F is the contrary to F, how could I explain "G is not F and not con-F"?
Thanks for your time read this.
Comments (41)
Is this the article?
If Plato were alive he would ask the same questions. The SEP has hundreds of articles on modern logic, and many on ancient Western and Eastern logic. Since there are so many different articles on the subject, it would seem not all logic is the same.
Although I know that this content will probably not be tested in the entrance exam,but I always feel that something is missing if I don't understand it.
Yes, but everyone else is also missing that understanding. There is plenty of interpretation and opinion. Some people think it was just a lesson in logic or even a joke, but I just don't think anyone truly thinks like Plato did at the time he wrote that piece. It's obvious that the dialogue was an important turning point in Plato's thought therefore cannot be ignored.
The SEP article is amazing just for un-jumbling the details for us to try to follow.
Well, The G is the one, and F is another property. So, "G is not F and not con-F" says that G is a different from F.
The purpose is to bring out the structure of each argument, and show that each is valid.
I'd favour the reading that what is shown instead is that the arguments reach contrary conclusions, and hence that the One is an incoherent notion.
At Notre Dame Phil Reviews (NDPR), John Palmer responded to Rickless' Parmenides in some detail.
Don't get me wrong, I love modern logical reconstructions based on Plato's work because they make for fun reading. But that's not the same as reading and attempting to make sense of the original dialogue. Rickless's F and G only say what Rickless wants them to say.
Quoting Banno
It would seem so.
Young Socrates fully agrees with the Parmenides character that particulars can't possibly exist but challenges Parmenides to show the same for the Forms. Part II is intended to prove that Forms are incoherent as well.
It is generally agreed that Plato was not fazed by this apparent debacle. That's because Plato had moved past these simple Aristotelian(!) modes of thought about the world, so that simple Aristotelian critique was no longer of direct concern to him. Correspondingly Plato wouldn't care what Rickless' logic said about a no longer Platonic "Theory of Forms".
That the Forms are hypothesis should be understood in light of what is said about hypothesis in the Republic. They are "stepping-stones and springboards" (511b). They are intended to free us from what has been hypothesized. In the Phaedo Socrates calls the hypothesis of Forms “safe and ignorant” (105c).
Given all the problems with the Forms we might ask why Plato did not just abandon them. Plato gives us the answer in Parmenides: One who does not “allow that for each thing there is a character that is always the same" will “destroy the power of dialectic entirely” (135b8–c2). Something like the Forms underlies (hypo - under thesis - to place or set) thought and speech.
The problem is, despite the mythology of transcendence in the Republic, we cannot achieve transcendence through dialectic. This is why the dialogues frequently end in aporia. What is at issue is not simply the problem of Forms but the problematic nature of philosophy. It raises insoluble problems.
Plato was a sceptic. The forms are totalities which cannot be conceived. But Plato invented the concept, which is based in skepticism.
An aporia is because you believe a total comprehension is possible
https://shwep.net/podcast/platos-parmenides-and-metaphysics/
Yes, of course, it is very easy to find out in the Web that it's from Parmenides Dialogue, but I wonder how this could help you answering what the topic asks ...
Isn't this too evident after reading that article??
Check this ref too: https://stanford.library.sydney.edu.au/archives/sum2012/entries/plato-parmenides/
I think we are generally in agreement.
Quoting Jackson
It is important to distinguish Socratic skepticism from other types, both ancient and modern. It is zetetic - it proceeds by way of inquiry based on the knowledge that one does not know.
Quoting Jackson
An aporia is an impasse. If, as in the Republic, there is a movement from hypothesis to knowledge, an aporia represents the failure of that movement. But zetetic skepticism is not the claim that total comprehension is not possible, but simply that it is not something that anyone possesses. The problem this raises, as described in the Phaedo, is "misologic" (89d-e). With the failure of logos Socrates turns to mythos. In terms of the image of the divided line in the Republic, it is recognition of the importance of eikasia, that is, the use of the imagination and image making.
Although things are said to be images of Forms, the Forms are themselves images. A kind of philosophical poiesis. What it seems must be if there is to be knowledge of things such as Justice, Beauty, and the Good.
Quoting Fooloso4
I do not see the difference.
Then reason depends on the imagination. Something which Plato spends his entire career denying.
I thought the quote in the OP could be made more explicit for discussion. But if you like guessing that's OK too.
The zetetic skeptic, unlike some other skeptics, does not deny the possibility of knowledge, claiming only that we do not know. Nor is it the suspension of judgment, but rather leaves open the possibility that we might be wrong about our judgments. It relies on what seems most likely, but remains open to revising these judgment about what seems most likely.
Quoting Jackson
The Republic is clear about the limits of reason (dianoia). It does not grasp each thing itself in its singularity (noesis), but always as it is in relation (ratio) to something else.That is to say, it makes use of likenesses (eikasia). Plato repeatedly points to the use of images for mathematics
I must be missing the point.
OK, but I answered your question afirmatively myself. Has that helped you? Has that made any difference?
This is an important point. It comes out much later with respect to the arguments about universals as the mechanism of meaning. As Plato believes that the objects of reason have a greater degree of reality than those of sense, then they must have something unchangeable as their object.
Could you say that Aristotle's later theory of essence and substance is foreshadowed here?
Quoting Fooloso4
I think, rather, that it indicates problems which can't be solved from the standpoint from which they are posed. In other words, that their resolution depends on reaching a higher perspective, in accordance with the steps of Diotima's ladder. That is something like 'the philosophical ascent'.
I've recently discovered why this notion of 'philosophical ascent' now seems such an implausible ideal. It is articulated quite clearly in this passage (referring to the 'scientific revolution'):
[quote=Alexander Koyré, 'From the Closed World to the Infinite Universe'] This scientific and philosophical revolution - it is indeed impossible to separate the philosophical from the purely scientific aspects of this process: they are interdependent and closely linked together - can be described roughly as bringing forth the destruction of the Cosmos, that is, the dissappearance from philosophically and scientifically valid concepts, the conception of the world as a finite, closed and hierarchically ordered whole (a whole in which the hierarchy of value determined the hierarchy and structure of being, rising from the dark, heavy and imperfect earth to the higher and higher perfection of the stars and heavenly spheres), and its replacement by an indefinite and even infinite universe which is bound toether by the identity of its fundamental components and laws, an in which all those components are placed on the same level of being. This, in turn, implies the discarding by scientific thought of all considerations based upon value-concepts, such as perfection, harmony, meaning and aim, and finally the utter devalorisation of being, the divorce of the world of value from the world of facts.[/quote]
That's the context in which 'the philosophical ascent' is unintelligible, for the simple reason that there is no longer a qualitative (i.e. vertical) axis along which there could be an 'ascent'.
Well, he certainly makes an argument in favor of this, but that is not the same as believing it. The Forms are posited as hypotheticals. A hypothetical does not have a "greater degree of reality" then sensible things. In various dialogues Plato gives us reasons to doubt the adequacy of the accounts of the Forms.
I discuss some of these problems
Here
and
Here
Quoting Wayfarer
The term essence (essentia) was a Latin invention used to translate Aristotle's Greek ousiai, or substance. Substance oressentia is the “the what it was to be” of a thing. His answer was not that what it is is a Form.
The Latin is wrong. By "essence" Aristotle means "form" or "shape." (eidos or morphê)
'Ouisia' is a form of the Greek word 'to be', and so the word is nearer in meaning to 'being' or 'subject'. It was translated into Latin as 'substantia' and thence English as 'substance' but it has a completely different meaning in philosophical than in everyday discourse.
And the Platonic forms were 'immanetised' by Aristotle as the forms of hylomorphism where they live on to this day. In later Scholastic philosophy, the form of the particular was what was known by the intellect, as distinct from the matter, which was known by sense.
@Jackson
From the Wike page on 'ousia':
Where I am from, using wiki to debate philosophy would get you laughed out of the room.
Concepts I'm familiar with that seem relevant:
1. Reflexivity. Equals: 2 = 2.
2. Symmetry. Sibiling of: If x is the sibling of y then y is the sibling of x.
3. Transitivity. Greater than (barring rock-paper-scissors sorta stuff): If x > y and y > z then x > z.
Translation of terms is not philosophy, it is a well documented matter of fact. There are, however, philosophical consequences.
Wayfarer asked:
Quoting Wayfarer
Aristotle did not use the terms 'essence' and 'substance'. In the long history since those terms were used to translate 'ousia' they have gained various meanings that should not be attributed to Aristotle.
You say:
Quoting Jackson
Aristotle did not use the term 'essence'. It is an English translation of the Latin 'essentia'. A term coined by Cicero to translate 'ousia'. Ousia, the term used by Aristotle, does not mean eidos or morphê. They are three different terms that have some overlap but have different meanings.
No, in the Physics, formal cause is "eidos" or "morphe". You are wrong that it is ousia. Ousia just means being or a thing.
I believe you are just wrong.
I did not claim that ousia is the formal cause.
Quoting Jackson
Which is what I actually said, several times. Except that the question of being qua being is of primary concern in the Metaphysics.
Quoting Jackson
Which part? That 'essentia' and 'essentia' are Latin terms used to translate 'ousia' or that these terms have accrued other meanings?
Quoting Jackson
Indeed, that is still the case!
Misunderstanding. My mistake.
I do not think we disagree on anything. My apology if there was offense based on my misunderstanding.
I appreciate it, but no apology necessary. Disagreement is standard practice in philosophy. I learned long ago that it is a mistake to take such things personally.
Good. I actually appreciate your contribution to this forum