I want here to look at Greek metaphysics as it is in the work of Plato and his pupil Aristotle.
As we know, the term 'metaphysics' itself was not used by the Pre-Platonics, nor even by Plato and Aristotle themselves. It arose centuries later - and somewhat accidentally - when an editor (1) of Aristotle's collected works serially named the book dealing with what Aristotle called 'First Philosophy', ta meta ta physika ['what comes after (the book of) Physics'].
The name having 'stuck', we can say in the broadest sense that 'metaphysics' deals with 'what there is' - i.e. with the basic nature of things, and any questions arising from this.
A claim such as 'everything is made from water' (2) can be seen as a meta-physical claim rather than a purely physical one because it aims at giving an 'account' (Greek, logos) of the ultimate reality. An account based not so much on sensory experience as on reasoning.
1) This was Andronicus of Rhodes, 1st century BC. He was the 10th head of the Lyceum which was set up originally by Aristotle.
2) The view of the Pre-Platonic Ionian philosopher Thales, 6th century BC; cf. Curd p.9
For Plato, the ultimate reality consisted of 'Forms' [eidos; - act of seeing; appearance, shape, form; beauty; notion, idea; kind, species (3)]. These Forms were said to be eternal and unchanging, like 'the One' of Parmenides (4).
Like the Pre-Platonics, Aristotle is concerned with the most general form of 'being' [ta onta, 'things that are' (5)], saying that he intends to "investigate being as being," (6) [on hei on, or 'being qua being' (7)]. This gave rise to the term 'ontology' as it was to be coined much much later during the so-called European Enlightenment (8).
'Ontology' was then codified into four branches;
Psychology [i.e., of the Soul]
Theology [i.e., of God]
Cosmology [i.e., of the Universe]
Ontology [i.e., of Being or Existence]
Using the framework of the above categories in the following sections I will compare the metaphysics of Plato and Aristotle..
3) Feyerabend, entry 'eidos'.
4) Curd, p. 43. See also Plato, Parmenides, ps. 920-957.
5) Burkert p. 307
6) Aristotle, Metap. IV:1, 1003a
7) Bernadette, p. 9
8) By The German philosopher Christian Wolff (1679-1754)
To Socrates, not only death, but enlightenment too, meant the separation of the soul from the body;
"Surely the soul can best reflect when it is free of all distractions, such as hearing or sight or pain or pleasure of any kind - that is, when it ignores the body and becomes as far as possible independent, avoiding all physical contacts and associations as much as it can, in its search for reality ... in despising the body and avoiding it, and endeavouring to become independent - the philosopher's soul is ahead of all the rest." (10)
In his later work, Plato not only professes the immortality of the soul, but also metempsychosis;
"He that grows better shall make his way to the better souls and he that grows worse to the worse, and so in life, and throughout the series of deaths." (11)
Now, while Aristotle believes in the soul, he does not believe it to have a personal immortality [and so rejects metempsychosis]. To him, "the soul is the form of the body" as it "confers unity upon a certain amount of matter" (12), and so cannot be thought of apart from the body which is a combination of form [eidos, morphe] and matter [hule].
However, Aristotle actually nuances his conception of the soul: while all living things [including plants] have a soul, only a few possess a rational soul, which is impersonal and divine (13);
"Certain living beings - a small minority - possess calculation and thought." (14)
In Plato, the soul "carries in it a knowledge which it has not won in this life: knowledge is recollection: anamnesis." (15) This is similar to Aristotle's notion of 'potentiality' [dunamis], which suggests that I could not gain knowledge, for example, unless I already possessed the potential. And as 'actuality' [energia, entelecheia] is prior to potentiality, "all knowledge comes from pre-existing knowing." (16)
10) Plato, Phaedo, 65a-d
11) Plato, Laws X, 904e
12) Russell, p. 130
13) ib., p. 167
14) Aristotle, On the Soul, II:3, 415a
15) Burkert, p.. 323
16) Ross, p. 175
Russell offers this interpretation of Plato's theology;
"God did not create everything - He created only what is good," and the Forms are "not so much created by God as constituents of His essence."
The "apparent pluralism involved in the multiplicity" of Forms "would thus not be ultimate. Ultimately there is only God, or the Good," to whom the Forms "are adjectival." (17)
Aristotle's God is the (unmoved) Prime Mover; the efficient and final cause of the Universe. Metaphysics was also called 'theology' by Aristotle as "the divine must be the first and most dominant principle." (18)
God, as the final cause, "moves not by mechanical agency, but by being desired and loved." (19)
God is pure mind: "It must be of itself that the divine thought thinks (since it is the most excellent of things), and its thinking is a thinking of thinking." (20)
But "Aristotle never uses the word 'providence' of God, as Socrates and Plato had done ... he has no interest as Plato has in justifying the ways of God to man." (21)
17) Russell, p. 130
18) Metap. XI:7, 1064a, cf. Burkert p. 329 and Russell p. 164
19) Ross, p. 175
20) Metap. XII:9, 1074b
21) Ross, p. 186
Regarded as the founder of scientific astronomy, Eudoxus (22) studied at Plato's Academy. He explained the movements of the planets by "postulating twenty-seven concentric spheres, each revolving in its own axis." (23) His work had a profound effect on the metaphysical cosmologies of Plato and Aristotle.
Plato wrote that "the belief that the sun, moon and other heavenly bodies are 'wandering stars' of any sort is not true. The very reverse is the truth - each of these bodies always revolves in the same orbit and in one orbit, not many, for all that it looks to be moving in several, and again the actually swiftest of them is wrongly believed to be the slowest and the slowest the swiftest." (24)
Plato describes the planets, or heavenly bodies, as deities and as having 'souls' (25) in his Timaeus, which, under the tutelage of a 'Pythagorean', "develops into a hymn on the animated divine cosmos. Ontology and cosmology sound together in harmony.." (26)
In general, Aristotle shares this basic view of the cosmos, although he eschews the arcane Pythagorean mathematisations of the Timaeus. In Aristotle, "the motions of the sun, moon and planets are explained by the hypothesis of a 'nest' of concentric spheres each with its poles fixed in the sphere next inside it, and the prime mover, by moving the outermost sphere, moves all the others." (27)
But he differed from his former master on one point: "it is clear that the theory that the movement of the stars produces harmony, i.e. that the sounds they make are concordant, in spite of the grace and originality with which it has been stated, is nevertheless untrue." (28)
This is in direct contradistinction to Plato who followed the Pythagorean theory of the music of the spheres, saying of the cosmos; "upon each of its circles stood a siren who was carried 'round with its movements, uttering the concords of a single scale." (29)
Aristotle's reason for rejecting this view is that if bodies of such tremendous size made a sound proportionate to that size, then we could not fail to hear that sound on earth - a view which nicely contrasts Aristotle's tendency towards an empirical approach in comparison to Plato's purely rational one.
22) Eudoxus of Chidos (c. 408 - 355 BC). Mentioned by Plato in Letter 13.360c [in Plato]
23) Dudley, p. 75
24) Laws VII, 822a
25) Burkert, p. 327
27) Ross, p. 181
28) Aristotle, On the Heavens, II:9, 290b
29) Plato, Republic, X.617
Plato explicates his 'Theory of Forms' in the parable of 'The Cave'. (30) We are to imagine ourselves born into an immobile incarceration inside a back-lit cave. Because we do not know any different, we take the shadows we see on the cave wall to be real things.
This 'seeing' itself is a metaphor for the soul; note how our vision is dependent upon the type and quality of light. In complete darkness we can see nothing - this is true ignorance. But in a cave, a fire-lit shadow-play easily creates an 'illusion' [eikasia]. In such a state we have at best only 'opinion' [doxa], not 'knowledge' [episteme].
Only in the open day-light of the sun can we see things as they are, when the soul is free from the fetters of the cave of ignorance and illusion.
This is the allegory of Platonic philosophy itself, as one who escapes the cave may not be ready for the powerful sun-lit Truth, and so be blinded. Or else he may want to return to the cave to open the eyes of the other benighted souls, only to be called lunatic for his pains.
He may even be put to death as was Socrates.
The world of Forms is hard to know;
"We should assume two classes of things, one visible and the other invisible." (31)
But everything in this visible world is a mere copy of a perfect Form, which latter reside in this invisible world, "the invisible being the invariable." (32)
Such copies only "partake" [methexis] of the Forms;
"It seems to me that whatever else is beautiful apart from absolute beauty is beautiful because it partakes of that absolute beauty, and for no other reason." (33)
30) Plato Republic VII 514a-517a
31) Phaedo, 79a
33) ib., 100c
Plato actually combines Heraclitean Becoming with Parmenidean Being. As Shelley (34) put it;
The One remains, the many change and pass;
Heaven's light forever shines, Earth's shadows fly.
This "Heaven's light" is the third element (35), known as 'the Good':
"The greatest thing to learn is the Form of Good by reference to which Just things and all the rest become more beneficial." (36)
This world of Forms is reality; it exists outside of our own minds, although it can be known - if only darkly - by pure ratiocination.
The world of appearance, which we recognise all too easily and viscerally, is unreal.
Plato's thorough-going dualism posits a divided line, with knowledge [of reality] on one side, and opinion [about appearance] on the other.
Reason is thus "concerned with pure Forms, and its method is dialectics." (37)
Dialectics, the process of question and answer which strives to arrive at 'justified true belief', and used to such effect by Socrates, is well-suited to uncovering knowledge via 'recollection' (15), but it is less suited to the study of empirical science. (38)
34) Shelley, Adonais LII (1821)
35) Rep. VI 507d
36) ib. 505a
37) Russell, p. 125
38) ib. 505a
We are now at the root of Aristotle's disagreement with with Plato.
Aristotle's ontology supports the logical 'laws' of contradiction (39) and excluded middle (40), whereas the Theory of Forms straightforwardly violates these: 'a thing is not real in the visible world, but it is real in the invisible world'! Or that "things always partake of opposite characters: what is beautiful is also, in some respects, ugly ... and so on. All particular sensible objects, so Plato contends, have this contradictory character; they are thus intermediate between being and non-being, and are suitable as objects of opinion, but not of knowledge." (41)
Such is roundly rejected by Aristotle, who claims that the senses are infallible - under the right conditions. (42) For Aristotle, 'substance' [ousia] is ontologically basic, and therefore is the foundation of metaphysics, and the first of his categories. (43)
'Substance' corresponds to the basic elements of his syllogistic logic, that of subject and 'predicate' [kategorein], which is - ontologically - substance and attribute.
But he also believed there to be three kinds of substance: that which is perishable and sensible [such as plants and animals, and studied in psychics]; that which is sensible but imperishable [such as the heavenly bodies]; and that which is neither sensible nor perishable [the rational soul of man and God, studied in metaphysics]. (44)
39) i.e., something cannot both 'be' and 'not be' at the same time.
40) i.e., that there is nothing intermediate between something being so, and its not being so.
41) Russell, p. 122
42) Ross, p. 163
44) cf. Russell, p. 104, and Ross p. 156
43) Aristotle counts ten categories in all [cf. Topics 9, 1036, and Categories 4, 16]
So substance bridges physics and metaphysics, and in the latter case we do have a separation of form and matter. However, it is not a clear-cut separation as in Plato, it is rather the result of a teleological evolution towards pure form.
And just as things can work towards pure form, so they can also - by the process of abstraction - work towards 'prime matter' in the other direction. Likewise, we can 'strip away' substance to its very 'essence' [to ti en enai, to ti esti];
"What we describe abstractly as the essence is, viewed concretely, sometimes a final, sometimes an efficient cause." (45)
The 'cause' [aitia, cause, reason, motive, explanation] is the explanatory factor in Aristotle's metaphysics. He recognised four 'causes', whereas previous philosophers had only recognised one or two at most, and so were unable to explain - in the case of Plato, for example, - things like change.
The material cause [as in Ionian philosophy] explains the 'stuff' from which a thing is made.
The formal cause [as in Platonism/Pythagoreanism] explains that which a thing is,
while the final cause (hou heneka) [as in Socrates/Plato] explains the purpose for the sake of which a thing comes about.
Only Aristotle - amongst the ancients - is able to encompass all the possible causes in his philosophy.
45) Ross, p. 173
It must be said that Plato had long acknowledged the problematic nature of his Theory of Forms in the Parmenides dialogue;
"If so, nothing can be like the Form, nor can the Form be like anything. Otherwise a second Form will always make its appearance over and above the first Form, and is that second Form is like anything, yet a third. And there will be no end to this emergence of fresh Forms, if the Form is to be like the thing that partakes of it." (46)
Known as the third man argument, and taken up again by Aristotle in his Metaphysics to attack Plato's theory, it shows that the Forms entail a logically impermissible infinite regress. Therefore Aristotle cannot allow that they have any kind of substantiality;
"Form is eternal only by virtue of the never-failing succession of embodiments. Form indicates a 'such', never a 'this'; a characteristic, never the concrete thing that bears it." (47)
To conclude; Aristotle's metaphysics is an attempt to 'improve' upon the Platonic, rather than a rejection of the same. Both Plato and Aristotle retain the core concepts of 'form', 'universals', 'God', 'soul', and the cosmic 'mind'. But Aristotle places a different emphasis - that of the logical and biological, against Plato's mathematical and mystical inclinations.
However, in avoiding the 'third man', does Aristotle not make his own notions of 'universals' and 'pure form' somewhat tenuous; and do not Aristotle and Plato rather provide two differing perspectives of one thing: 'Greek Metaphysics'?
46) Plato, Parmenides, 133a
47) Ross, p. 175
Aristotle, The Works of Aristotle, Oxford 1952
Bernadette, Metaphysics, the Logical Approach, Oxford 1989
Burkert, Greek Religion, trans. Raffan, Blackwell 1985
Curd, ed. A Presocratic Reader, Hackett 1995
Dudley, ed. Penguin Companion to Literature 4, 1969
Feyerabend, ed. Greek Dictionary, Hodder and Stoughton 1966
Frankfurt et al. Before Philosophy, Pelican 1949
Honderich, ed. The Oxford Companion to Philosophy, 1995
Kramer, Plato - The Foundations of Metaphysics, New York 1990
Plato, The Collected Dialogues, ed. Hamilton/Cairns, Princeton 1961
Ross, Aristotle, Methuen 1923
Russell, History of Western Philosophy, Routledge 2004
Schlesinger, Metaphysics, Oxford 1983
Shelley, The Works of P.B. Shelley, Wordsworth 1994