Tradition states that Parmenides was a Pythagorean -- which is apparent first of all in the radical dualism that emerges here.
Like Heraclitus, the dualism between Being and Seeming is balanced by a thrust of unity in terms of the original insight -- truth as a well-rounded whole (see p. 268).
Estin e ouk estin -- either a thing is or it is not
the only way of enquiry that can be thought of (that exist for thinking) that it is and cannot not-be.
(In contrast with: that it is-not and needs must not-be -- this is unthinkable: "for you could not know that which is, nor utter it."
Mortals are persuaded that to be and to be-not are the same, yet not the same -- helplessness guides the wandering thought in their breasts.
The judge is reason -- logos.
Given that "it-is," -- that what-is, is -- what-is, is entire, immovable, and without end.
Neither past nor future, but now, all at once, one, continuous.
Creation is not possible, because that implies creation out of some thing different from what is, but that would be what-is-not -- which cannot be.
Or, for logicians:
Creation [of what-is] --> creation out of something different from what is
A --> B
Something different from what-is = what-is-not
B --> C
But what-is-not cannot be.
C --> ~E (non-existence)
[non-existence is inadmissible, a contradiction: ~~E ]
Therefore, creation is not possible: ~E
That is, this argument combines what later logicians will call deductive syllogism [ A --> B --> C --> ~E ] and denial of the consequent [ A --> ~E, ~~E, /.. ~A ]
--> his point of difference with the Pythagorean cosmogony, in which the unit is placed within the unlimited, and the void is inhaled.
The denial of the void also leads to the claim that what-is, is not divisible, but homogeneous, continuous and hence, what-is is motionless, finite, like a sphere (?)
We then end with the Heraclitean insight: names, such as coming into being and perishing, being and not-being, change of place and variation of bright color -- are mere names.
The large historical problem should become clear: (1) the monistic starting point, (2) coupled with the reliance on reason (logos) to achieve the proper account (logos) of the order of things (logos) -- concludes in Parmenides' hands with a radical dualism, one which reduces the world of appearances to mere appearance, illusion.
Out of this problematic will emerge Heraclitus' effort to "save the appearances," an effort continued by the Pluralists -- indeed, through Plato and his school.
From Kirk & Raven: Parmenides and the Eleatic School
Parmenides is the most significant of all the Pre-Socratic philosophers, insofar as he represents the appearance of metaphysics.
Up until his time, Greek speculation had been cosmological, physical, with a philosophical purpose and method: it is Parmenides who discovers the proper theme of philosophy and the method by which this them can be approached.
The theme -- metaphysics/ontology. In Parmenides' terms, Entity [eon] or Being [on] is the object of inquiry.
The method: nous (mind, mens in Latin) -- roughly, mind, intelligence, perhaps spirit.
Parmenides was influenced by Xenophanes (though it is unlikely that they knew each other) and by the Pythagoreans.
His proem, "On Nature," describes "the two ways," -- the way of truth, and the way of opinion.
Expressed metaphorically, the daughters of the sun guide the poet on the road of the goddess. They draw aside their veils, leave the abode of night (which is guarded by justice). The goddess greets Parmenides and tells him that it is necessary for him to learn everything, "The inviolable heart of well-rounded truth, as well as the opinions of mortals, who do not possess true certainty." There is but one way of life.
There is here a "clear allusion to the passage from mythical to theoretical consciousness." The daughters of the sun have rescued Parmenides from darkness.
The metaphor of the veils stands for truth -- an unveiling or discovering, aletheia.
A simple, but fundamental schema correlating ontology and epistemology (an account of episteme, of how we know and what we can know) emerges:
|Means of Knowledge||Object of Knowledge||Way of Knowing|
of truth (the way of "what-is",
of impasse (the way of "what-is-not")
|sensory perception (aisthesis)||
|of opinion (the way of "what-is" and "is-not")|
The Way of Truth
On, Entity -- is present. The things, insofar as they are, are present to the mind, nous). The Entity neither was nor will be: it is now, in the present. On, (ens in Latin) is a present participle. Things can be far away or close to the senses, either present or absence -- but as entities, as beings (in Platonic terms, as "participating" in Being) they are contiguous with nous.
All things are entities -- i.e., they are. In some sense, they are enveloped by Being -- and hence united or one. The multiplicity of things does not affect the oneness of the Entity: Entity/Being is, qua Being, one. Hence, Parmenides arrives at the statement that the Entity is a sphere without spaces of non-being.
Entity is immovable. Motion is understood as a mode of being. Coming to be or ceasing to be implies a duality of entities, and the Entity is one, -- homogeneous and indivisible. If I divide a thing into two parts -- both parts still are: Being is unaffected, it remains one and undivided.
The Entity is full -- it has no empty spaces: it is continuous and all inclusive. (This is an argumentum ad absurdum: something outside the Entity would not be -- because it is removed from Being. But if something being were somehow outside the Entity, it would be, and hence would be included within Entity.)
Entity is uncreated and imperishable. The contrary would imply a non-being, which is impossible. (This is the conceptual precursor to the physical principle: matter is indestructible.)
The Way of Opinion (doxa):
Within the sphere of truth, there can be either truth or falsity.
This way depends on sense-data -- information about things. This information is manifold and capable of changing.
Opinion understands this change as a coming-to-be -- which is its primary mistake. Being is discovered not by the senses, but by nous. The lack of nous means that the opinion/sense-data version of what-is (e.g., Thales', etc.) is unreliable, and "merely" opinion.
Opinion is the opinion of mortals -- by way of aisthesis, sense-perception. It is composed of opposites, which are mortal, imperishable. But opinion is thereby devoid of nous which is divine and immortal, just as Being is.
Motion is light and darkness. Coming-to-be is only apparent - things which come to be already existed, but in darkness. Motion is "really" only the shift from darkness to light -- not generation from non-being to being. From the point of view of Being, such generation is only illusion -- it does not exist.
Motion or change is convention (nomos) -- names which men give to things.
Things (pragmata) show manifold properties to the sense.
But when considered with mind (nous), they manifest a property of the greatest importance, common to all: they all are.
Being is an essential property of things -- but this property only shows itself to mind, to nous. Things from this standpoint are onta, be-ings.
Nous and on are essentially related. For Parmenides, the one does not occur without the other: in this sense, they are the same:
When seen through nous, the Entity is one, immovable;
When seen through aisthesis, things are manifold (plural) and changeable.
Philosophy now becomes ontology, no longer physics. In fact, since Entity is immovable --- since motion is, from the standpoint of Being, illusory -- physics is impossible.