We left off last time with Parmenides having trashed everything that went before him by arguing that, since what-is-not is-not, and only what-is is, there could be no change and no differentiation.  For change and differentiation entail something besides what-is, namely what-is-not, and what-is-not is-not.  If we take this argument at face value, it means that there is only one thing in the universe, namely what-is.  It has, as we have seen, four Eleatic properties: (1) it is without coming-to-be and perishing, (2) it is all alike and undifferentiated, (3) it is unchanging in any way, and (4) it is complete.  This sounds like a very austere Monism, with only One Thing in existence, and no bells and whistles to accompany it. 

But there is another chapter to the story.  In his philosophical poem, Parmenides has the goddess who instructs the youth tell him about another approach to the world:

Here I cease from faithful accounts and thought

about truth: from this point on learn mortal opinions,

hearing the deceptive order [kosmos] of my words.

For they [mortals] made up their minds to name two forms [morphai],

of which it was not right to name one—this is where they have gone astray—

and they distinguished contraries in body and set signs

apart from each other: this this form the ethereal fire of flame,

being gentle, very light, everywhere the same as itself,

not the same as the other; but also that one by itself

contrarily unintelligent night, a dense body and heavy.

I declare to you this arrangement [diakosmos] to be completely likely,

so that no judgment of mortals will ever surpass you.  (fr. 8. 50-61)

Here the goddess offers an explanation of the cosmos based on a combination of two stuffs, fire and night, or, as Aristotle later calls them, fire and earth.  Each one is “the same as itself” and in itself changeless, but by combining with the other in different proportions, it produces different outcomes. 

The goddess goes on to develop her own cosmology based on this scheme, one which she promises is “completely likely.”  But of course she has introduced the whole scheme by saying that it is “deceptive.”  So what are we to make of this second philosophical excursus?  Is it, on the one hand, the best and most promising account we can have of how the world works?  Or is this just a device to show us that the best possible account of the world is doomed from the outset, based on a mistake, namely positing the existence of a second reality, which is ruled out by the first part of the poem?  There are modern proponents of both of these interpretations: the one saying that there is a way out of the dead-end Parmenides’ goddess presented in the first part of the poem; and one that says there is no way out, only an object lesson in the failure of all quasi-scientific approaches to the world. 

For now, though, let’s not try to answer this philosophical question, but rather a historical one: what did Parmenides’ successors think he was doing in the second half of the poem? 

Most twentieth-century commentators have assumed that Parmenides’ scientific-minded successors recognized the threat from Monism of the first half of the poem and desperately tried to save philosophy from it.  But, according to these commentators, they failed miserably.  Yet if we look the writings of his first successors, they never try to refute or criticize Parmenides at all, but rather they seem to acknowledge his ideas as important directives for themselves.  Remember how Anaxagoras and Empedocles warned that there was no real coming-to-be or perishing (Eleatic property 1), but only combination and separation.  What they do, without arguing against Parmenides at all, is to adopt theories in which there is a plurality of real beings, much as in the case of goddess’s cosmological model, in which there are two basic substances, one rare, light, and bright; one dense, heavy, and dark.  They mix together to produce entities of intermediate density, weight, and luminosity.  In fact, what the goddess gives us in her revisionary cosmology is a theory of elements: changeless entities with fixed properties of their own that can combine into (temporary) mixtures or compounds with new or “emergent” properties.  And that is what we get from Anaxagoras and Empedocles: a set of permanent elements that, in combination with each other, produce the variegated texture of the world. 

It looks very much like Anaxagoras and Empedocles saw themselves as followers of Parmenides and his Eleatic critique, not opponents.  They seem to have seen the second half of the poem as a positive program for the reform of cosmology and science in light of the objections against earlier theories of the first half of the poem; Parmenides offers a remedy for cosmology, not a death knell.  Were they mistaken?  Possibly.  But consider one other issue that comes into play here.  Parmenides’ “deceptive” cosmology is much better scientifically, amazingly so, than those of his predecessors.

Parmenides gives us three new ideas, hypotheses we might call them in a scientific setting, about the cosmos.  First, the Earth (I will capitalize to distinguish the heavenly body from the stuff it is made of) is spherical.  All previous Greek philosophers had posited a flat Earth, either a disk or a flat unbounded surface.  What reasons he had for proposing this we don’t know, or whether those reasons were empirical or theoretical.  But he first provided that possibility.  Second, he said that the Morning Star was the Evening Star, in other words, that the former and the latter were the same body, the planet Venus in our terms.  The Babylonians had known this for a thousand years before Parmenides, but the Greeks were not aware of their discovery (indicating an unfortunate lack of communication on astronomical topics among the cultures), and Parmenides lived far from Mesopotamia at around the time of the Persian Wars, when friendly communication between Greece and the Middle East was difficult at best.  Third, he said that the moon gets its light from the sun, and provided the empirical evidence: the shiny part of the moon is always facing the sun (frs. 14, 15).  These suggestions provide not just an interesting sidelight, but a stunning leap forward in astronomy and cosmology.  Anaxagoras would go on to use the last insight to develop the correct account of eclipses, both solar and lunar.  There had been many speculative theories of the moon’s light and its phases, and of eclipses, but not until now did any thinker get it right.  And when Anaxagoras announced his theory, all competing theories quickly disappeared.  A philosopher had finally got something right about the heavens, and everyone knew it.   

So whatever the Parmenides’ intentions in proposing his “deceptive” cosmology, it took the world by storm as the Next Big Thing in philosophy. 

Notice that the theory of elements was not just new, but powerful.  It presupposes that there is a set of changeless entities that have Eleatic properties, but that can interact to produce diverse phenomena, of the sort we observe in the cosmos.  And the theory was invented not by the Pluralists, but by Parmenides, in developing his “deceptive” cosmology.  It was based on a more fundamental idea.  In positing Eleatic properties, Parmenides had, in effect, recognized the notion of an Essence, a definable, permanent nature that characterizes real beings.  If you recall, the alleged Material Monists did not seem to have a concept of the identity conditions of a thing such that one could distinguish how something was “really” water when it lacked the sensible properties of water.  But if you recognize that there are essential properties that constitute the nature of a thing, not all of which properties are sensible, then you can reasonably claim that something is really water even when it does not look like water.  For instance, if we can, with a spectroscopic analysis of a sample of gas, determine that it is H₂O (which is the essence of water to modern science), then we can say it is water (vapor) even when it lacks the sensible properties of liquid water.  Modern chemistry is an application of the general theory of elements invented by Parmenides.

Notice, too, that the theory of elements gives a plausible answer to the Eleatic Challenge: how can what-is come to be from what-is-not?  A new compound can come from the combination of two or more elements that are.  Each element is-not the compound, but it is something.  We will have to be subtle with our semantics, but we can now deal with plural things-that-are, and accept a new theory of matter.  We can call it Pluralism, and, in keeping with its historical origins, Eleatic Pluralism: there is a plurality of beings with Eleatic properties.

Let us now recap the Beginnings of Philosophy by recognizing the stages it went through:

1. Every (derivative) stuff comes-to-be from and perishes back into some original stuff.  (Generating Substance Theory)
2. If (1), then every stuff changes into every other stuff, and only the pattern of change is constant.  (Heraclitus)
3. If (2), then what-is comes-to-be from what-is-not; but what-is-not is-not; so there is no change and no differentiation.  (Parmenides)
   1. We can make sense of change by allowing for a plurality of beings with Eleatic properties that interact with each other.
4. The world and its components and processes are explained by positing a plurality of Eleatic beings.  (Eleatic Pluralism)

The Eleatic Challenge posed by Parmenides did not go away.  But the model he provided in the second half of his poem, whether it was meant as a positive solution or as a killer objection, bore fruit in a new generation of scientific explanations.  It would be left to Plato (in his dialogue The Sophist) and Aristotle (in his treatise Physics I) to provide an articulate theoretical reply to Parmenides’ objections.