Traditional founder of philosophy. Lived in Miletus on coast of Asia Minor.
Predicted eclipse of 585 BC, prob. by use of Babylonian records.
Held that the arche of all is water. Interpretations:
(1) arche = explanatory first principle, in this case the "stuff" out of which all is made. (Aristotle)
(2) arche = source or beginning, so that Thales is simply extrapolating from the fact that life begins from and requires water. (Modern scholars)
Note explantion of earthquakes and argument that magnet possesses soul; shows his break from mythological patterns of thought.
Pupil and successor of Thales.
First person to draw a scaled map of the world; shows tendency to think in terms of models.
Author of earliest surviving fragment of Greek philosophy: coming-to-be and destruction happen "according to necessity; for they [elements? existing things?] pay penalty and retribution to each other for their injustice according to the assessment of time." Note belief in cosmic law (cf. Hesiod).
Held that the arche of all is the apeiron, the "unbounded" or "unlimited." Interpretations:
---(1) The apeiron is the stuff that underlies transmutation of elements (earth, water, air, fire). Since it is common to all elements, it has no fixed nature of its own, and is in that sense "unbounded." (Aristotle)
---(2) The apeiron is the infinite primeval void from which all things come forth and to which they return, as described in the fragment. (Modern scholars)
Author of first non-mythological cosmogony. Cosmos begins with the apeiron; then comes "that which is productive from the eternal of hot and cold"; then the rings of fire which we see (through peepholes!) as sun, moon, and stars; then evolution of living things. Explains eclipses, phases of moon as due to clogging up of peepholes.
Younger contemporary of Anaximander.
Held that the arche of all is air, which takes on different forms (earth, water, etc.) through rarefaction and condensation. A way of reducing qualitative difference to quantitative difference.
Undermining of traditional religion: held that gods arose from air rather than vice versa, and that the sun is simply earth heated by friction.
Emigrated from Samos (near Miletus) to Croton in sourthern Italy. Founded a secret brotherhood that still survived at time of Plato. Revived in first century BC and influential thereafter.
Discovered Pythagorean Theorem and mathematical basis of music. Made flying leap to infer that all things somehow "are" (= are composed of? are governed by?) numbers. In retrospect, a way of groping toward the formal as opposed to the material aspect of things.
Held 10 to be the perfect number, symbolized by the Tetractys of the Decad.
Believed in "music of the spheres" and that earth and the other planets revolve around the sun. Posited an unseen platent opposite to earth to make total number of heavenly bodies come out to 10.
Believed in immortality (Egyptian influence?), transmigration of souls, and eternal recurrence.
Rules observed by the Pythagorean brotherhood reflect belief that "all living things are akin" . Probably also a way of purifying the soul to secure the best possible reincarnation.
Pythagorean Table of Opposites (see Aristotle, Metaphysics I.5 [BK 352]):
Exemplifies Greek tendency to think in terms of polar opposites. Anticipates Aristotelian distinction between matter and form.
From Colophon (north of Miletus); emigrated to Sicily about 545 BC.
Criticized traditional beliefs about the gods. Main objections were (a) the traditional portrayal of the gods as engaging in adultery, theft, and deception is an insult to the divine; (b) to suppose that the gods are like men at all (= anthropomorphism) is provincial.
Believed in one god who remains always the same and "moves everything by the thought of his mind." Probably did not conceive this god as immaterial, however.
Skeptical about the possibility of human knowledge; distinguished knowledge from true belief.
Lived in Ephesus (north of Miletus), c. 540-480 BC. Known in antiquity as ho skoteinos, "the dark one," because of the enigmatic character of his sayings.
Central idea is the Logos (from legein, to speak). Possible meanings: word, speech, reasoned account, reason, ratio, proportion. What does it mean for Heraclitus? Some key evidence:
--the Logos can be communicated but is rarely understood 
--"all things happen according to this Logos" 
--"the Logos is common" 
--"listening not to me but to the Logos . . ." .
Conclusion: the Logos seems to be both a true description of reality and the governing principle of reality. Cf. the role of fire in  and . Also: "thunderbolt steers all things" (not in BK).
The Logos teaches that "all things are one" . Apparently to be understood in terms of unity of opposites [12, 14], relativity of perception [17, 18, 32, 33], and tension-in-rest [19-21]. An answer to the Pythagorean tendency to think in terms of opposites.
See also the following: "They do not understand how being at variance it agrees with itself; there is a back-stretched connection, as in the bow and the lyre" (not in BK). The power of the bow and beauty of the lyre depend on their inherent tension. Is emphasis on the necessity of tension & strife a reply to Anaximander?
Like Pythagoreans, Heraclitus has a concern for the state of the soul; see  and .
Also has a new awareness of the depth of the soul. "I sought myself" . Also: "You would not discover the limits of the soul although you traveled every road; it has so deep a logos" (not in BK).
Lived in Elea in southern Italy, c. 515-450 BC. Interest in philosophy awakened by Pythagoreans; also said by Plato and Aristotle to have been influenced by Xenocrates (though this is doubted by modern scholars).
Distinguishes two ways of enquiry: "that it is and cannot not-be," and "that it is-not and cannot be" . Only the former can be thought or spoken!
Why? Because "the same thing is there both to be thought and to be" . Parmenides thinks of thought and language as operating by latching onto things, so if something is not it can neither be thought nor spoken. Cf.  and .
Beginning of  lays down four requirements on being or "what is":
(1) has no coming-into-being and no destruction
(2) whole and of a single kind ("whole of limb" a mistranslation)
(3) without motion, i.e., immovable
(4) complete ("without end" a mistranslation).
Remainder of  argues for these in order. Most important argument is that for (1). Can be broken down into two sub-arguments:
(D) "How, whence sprung? . . . . What necessity impelled it . . . to be produced later rather than earlier?" A challenge to make the idea of coming-to-be intelligible.
(E) "Nor shall I allow you to speak or think of it as springing from not-being; for it is neither expressible nor thinkable that what-is-not is." An appeal to the prohibition against the second way of enquiry.
These two arguments had very different fates. (A) was taken seriously by virtually all later philosophers and became a major motivation for the Pluralists (Empedocles, Anaxagoras, and the atomists). (B) was largely ignored until Plato.
How do modern scholars deal with (B)? By arguing that Parmenides’ use of the verb 'is" is ambiguous. Seems to run together at least three different senses of "is":
(2) existential: x exists
(3) predicative: x is F
(4) veridical: it is the case that p.
Veridical makes the best sense of , , and , whereas existential is required in . Thus the argument fails because of a crucial ambiguity.
Parmenides and his followers, Zeno and Melissus, are known collectively as the "Eleatics."
From Acragas in Sicily; also traveled in southern Italy and the Peloponessus. Clearly influenced by Pythagoreans and Parmenides. Lived c. 492-432 BC.
A charismatic figure: poet, statesman, philosopher, physician, miracle-worker. Said to have kept a woman alive, without pulse or breathing, for thirty days. Honored as a god by the people of Selinus (near Acragas) for freeing them from a pestilence; cf. "I go about among you as an immortal god" . According to legend, hurled himself into Mt. Etna to confirm that he was a god.
Claimed to be a daimon (divine being intermediate between gods and men) who was exiled to earth because he had committed bloodshed and "trusted in raging Hate" . Could remember his previous lives . Was working to return to his divine state (or had already done so?) by purging himself of the defilement incurred through Hate.
Other people and animals are also former daimones. They simply do not know it. Hence it is forbidden to eat meat, a "harsh-sounding slaughter"  that perpetuates the defilement incurred through Hate. Also forbidden to eat certain plants:
"Keep completely away from laurel leaves!" (not in BK)
"Wretched, wholly wretched! Keep your hands off beans!" (not in BK).
These ideas clearly show Pythagorean influence. Note, however, that he uses the term daimon rather than psuche (soul). A way of emphasizing our supernatural origin and destiny, and the idea that life here on earth is a kind of exile.
Love (philia) and Hate (or Strife, neikos) also important in his physics. Each dominates in turn according to a kind of cosmic oath:
"But when great Strife was nourished in the limbs
And leapt up to its rightful prerogatives as the time was fulfilled
Which is established for them in turn by a broad oath . . ." (not in BK).
The Empedoclean "cosmic cycle":
(i) Initially Love predominates, so that all things are together in a single, homogeneous, spherical mixture (-).
(ii) Under the influence of Strife, the four elements gradually separate (, , ). Apparently this process occurs in a vortex () = the current rotation of the cosmos?
(iii) A stage of total separation, with the four elements arranged spherically: fire on the outside, then air, then water, then earth at the center.
(iv) Love again begins to dominate, drawing the elements back together. Eventually the cosmos returns to (i) and the cycle starts over again.
Stages (ii) and (iv) are mirror images of one another: "He says that the cosmos is in a like state both now in the period of increasing Strife and previously in the period of increasing Love" (Aristotle, not in BK). Cf. Pythagorean belief in eternal recurrence.
Also note that, though Strife is evil , Love needs Strife in order to produce an ordered cosmos. A nod to Heraclitus?
The entire scheme is implicitly an answer to Parmenides. Empedocles accepts from Parmenides that there can be no coming-to-be out of nothing or passing-away into nothing , as well as that reality is a plenum (, ). He preserves the reality of change by holding that what appears to be coming-to-be and passing-away is actually just combination and separation of the elements (, ).
The elements thus satisfy the Parmenidean requirements on being: they never come into being or pass away, are whole and of a single kind, unchangeable, and complete (, ). In essence, Empedocles has enunciated the first "conservation principle."
Born in Clazomenae in Ionia, c. 500 BC. Came to Athens c. 480 BC. A close friend of Pericles, who saved him from condemnation for impiety. Died c. 428 BC.
Like Empedocles, accepts the Parmenidean principle that there can be no coming-to-be from what is not. Interprets "is" in predicative sense: no coming-to-be F from what is not F .
Also like Empedocles, explains apparent coming-to-be and passing-away as due to mixing and separating of some fundamental "stuffs" .
What are these stuffs? Qualitative opposites like moist and dry, hot and cold, bright and dark ; also substances like air and aether , earth , hair and flesh . Note that he conceives a quality as just another material stuff that can be mixed with or separated from other stuffs.
The number of such stuffs is very large and may be infinite (Aristotle, Meta. I.3 [BK 349]).
"All things contain a portion of everything" . That is, within any portion of a given stuff, no matter how small, there are portions of all other stuffs.
Why? Follows from attempt to explain coming-to-be and passing-away in accordance with . Cf. the following from Simplicius (not in BK): "Seeing that everything comes to be from everything" if not immediately at least in sequence (for air comes from fire, water from air, earth from water, stone from earth, and fire again from stone, and when the same food, such as bread is assimilated, many things of different kinds come to be: flesh, bones, veins, sinews, hairs, nails, and in some cases feathers and horns, and like grows by means of like)—for these reasons he supposed that in the food, even in water if trees are nourished by this, are wood, bark, and fruit. That is why he claimed that all things are mixed in all things.”
The one exception is Mind (nous, from noein, to recognize). If Mind were mixed with anything it could not rule that thing, so it must be pure and unmixed .
Mind set in motion the "universal revolution" by which all things were separated off; it also understands all things and arranges all things . Though it is pure and unmixed, it permeates the cosmos .
Is Mind Anaxagoras’s version of God?
10. Leucippus & Democritus
Democritus (c. 460-360 BC) was from Abdera in Thrace. Extremely prolific: over seventy books, none of which survive. Little known of Leucippus save that he was the first atomist and was Democritus’s teacher.
The Paradox of Divisibility. Consider the following argument advanced by Zeno of Elea against the possibility of a plurality of objects.
Each thing that exists must have some size and thickness, and part of it must be apart from the rest. The same reasoning holds concerning the part that is in front: that too will have size, and part of it will be in front. Now it is the same thing to say this once and to keep saying it forever. For no such part of it will be last, nor will there be one part not related to another. Therefore, if there are many things, they must be . . . so large as to be unlimited. (not in BK)
What this argument actually shows is that, assuming infinite divisibility, any object has an infinite number of parts, each with some magnitude. If one adds the (seemingly innocuous) premise that the sum of an infinite number of magnitudes is itself infinite, one comes to the conclusion that any object with parts must be infinitely large.
According to Aristotle (De Gen. et Corr. I.2 [not in BK]) it was concern over this argument, and others like it, which led the atomists to speculate that matter is not infinitely divisible. The word "atom" (atomos) literally means "uncuttable."
Some characteristics of atoms:
--"compact and full," i.e., without parts and intrinsically unchanging (, )
--no properties other than size, shape, arrangement, and orientation (cf. Aristotle, Metaphysics I.4 [BK 351])
-infinite in number (, )
--infinite variety of shapes 
--join together by hooks, etc.  (NB no forces as in modern physics)
--too small to be seen? (, but cf. )
Besides atoms there is the void (to kenon, "the empty"). Not to be confused with space. Atoms are in space and surrounded by the void, much as a fish is in an aquarium and surrounded by water.
The void is "not-being"  or "non-existent" . A direct challenge to Parmenides. Note, however, that each atom, taken simply in its own right, satisfies the Parmenidean requirements on being.
Two further features of atomism are summarized in the sole surviving fragment of Leucippus: "nothing happens at random; everything happens out of reason and by necessity" (BK 40).
--Everything happens for a reason. An appeal to the idea later known as the Principle of Sufficient Reason: "no fact can be true without a sufficient reason for its being so and not different" (Leibniz). See especially the argument that the number of shapes of atoms is infinite . Similar reasoning probably lies behind the assumption that the number of atoms is infinite and the number of worlds (kosmoi) is infinite .
--Everything happens by necessity. Atoms move as they do because of collisions with other atoms , so that every event follows necessarily from antecedent physical conditions. Since even the mind is a physical entity composed of atoms , this means that the atomists implicitly deny free will.
Atomists sharply distinguish reality and appearance. In reality there are only atoms and the void; sensible qualities such as sweet, bitter, etc. exist by convention (nomos) only . Anticipates the modern distinction between primary and secondary qualities. The idea was not nearly as revolutionary in antiquity as in the 17th century, however, for at least two reasons:
Did not have behind it the full weight of science; atomism remained a minority view.
Atomists did not identify human existence with a consciousness that is "trapped" at the level of the secondary. For them, as for other ancient thinkers, man and nature remain integral parts of a larger whole. Epitomized in the notion that man is a microcosm . Cf. E.A. Burtt, Metaphysical Foundations of Modern Science, p. 89.
This may be why, despite what appears to us the radical nature of the atomists’ physical teaching, their ethics is surprisingly conservative. A few points to note:
---elevation of soul over body (, )
---importance of duty and acting from a sense of honor (-, , )
---virtue is to not want to do wrong 
---opposition to relativism 
---piety toward gods 
---social conservatism (, -, , )
---ambivalent attitude toward hedonism (, , , , ).