## 1. Who Were the Presocratic Philosophers?



Fragmentary evidence complicates our understanding of the
Presocratics. Most of them wrote at least one "book"
(short pieces of prose writing, or, in some cases, poems), but no
complete work survives. Instead, we depend on later philosophers,
historians, and compilers of collections of ancient wisdom for
disconnected quotations (fragments) and reports about their views
(*testimonia*). In some cases, these sources were themselves
able to consult the works of the Presocratics directly. In many
others, the line is indirect and often depends on the work of Hippias,
Aristotle, Theophrastus, Simplicius, and other ancient philosophers
who did have direct access. All of the sources for the fragments and
testimonia made selective use of the material available to them, in
accordance with their own special, and varied, interests in the early
thinkers. (For analyses of the doxographic tradition, and the
influence of Aristotle and Theophrastus on later sources, see Mansfeld
1999; Runia 2008; Mansfeld and Runia 1997, 2009a, and 2009b; Laks and
Most, 2016.) Despite (or perhaps because of) the fragmentary nature of
the evidence, new material occasionally comes to light. In 1962
"The Derveni Papyrus," probably dating from the second
part of the fourth century B.C.E., was discovered in Greece (Betegh
2004, Janko 2001, Kotwick 2017). It is primarily concerned with Orphic
religion, including a commentary on a poem attributed to
Orpheus. Through the work of scholars to reconstruct and interpret it
(see Kouremenos, Passoglou, & Tantsanaglou 2006) it has
become clear that the author of the commentary was familiar with the
philosophical theories of the time, and the papyrus has proved
valuable to the study of early Greek Philosophy (see, for instance
Betegh 2014a and 2014b, and Betegh & Piano 2019). Further new
Presocratic material was found in a papyrus from Upper Egypt, now in
Strasbourg, that contains texts from Empedocles, some already included
in DK, but also previously unknown lines which have complicated our
understanding of Empedocles' thought. (See Martin &
Primavesi 1999, and Janko 2001, 2005.) Although any account of
Presocratic thinkers has to be a reconstruction, we should not be
overly pessimistic about the possibility of reaching a historically
responsible understanding of them.



Calling this group *Presocratic*  raises certain difficulties.
The term, coined in the eighteenth century, was made current by
Hermann Diels in the nineteenth, and was meant to mark a contrast
between Socrates who was interested in moral problems, and his
predecessors, who were supposed to be primarily concerned with
cosmological and physical speculation. "Presocratic," if
taken strictly as a chronological term, is not accurate, for the last
of them were contemporaneous with Socrates and even Plato. Moreover,
several of the early Greek thinkers explored questions about ethics
and the best way to live a human life. The term may also suggest that
these thinkers are somehow inferior to Socrates and Plato, of interest
only as their predecessors, and its suggestion of archaism may imply
that philosophy only becomes interesting when we arrive at the
classical period of Plato and Aristotle. Some scholars now
deliberately avoid the term, but if we take it to refer to the early
Greek thinkers who were not influenced by the views of Socrates,
whether his predecessors or contemporaries, there is probably no harm
in using it. (For discussions of the notion of Presocratic philosophy,
see Long's introduction in Long (ed.) 1999, Laks 2006, the articles in
Laks and Louguet 2002, and Laks 2018.) 



A second problem lies in referring to these thinkers as
*philosophers*. That is almost certainly not how they could
have described themselves. While it is true that Heraclitus says that
"those who are lovers of wisdom must be inquirers into many
things" (DK22B35/LM9D40), the word he uses,
*philosophos*, does not have the special sense that it acquires
in the works of Plato and Aristotle, when the philosopher is
contrasted with both the ordinary person and other experts, including
the sophist (particularly in Plato), or in the resulting modern sense
in which we can distinguish philosophy from physics or psychology. Yet
the Presocratics certainly saw themselves as set apart from ordinary
people and also from others (certain of the poets and historical
writers, for example, as we can see from Xenophanes and Heraclitus)
who were their predecessors and contemporaries. As the fragment from
Heraclitus shows, the early Greek philosophers thought of themselves
as inquirers into many things, and the range of their inquiry was
vast. They had views about the nature of the world, and these views
encompass what we today call physics, chemistry, geology, meteorology,
astronomy, embryology, and psychology (and other areas of natural
inquiry), as well as theology, metaphysics, epistemology, and ethics.
In the earliest of the Presocratics, the Milesians, it can indeed be
difficult to discern the strictly philosophical aspects of the views
in the evidence available to us. Nevertheless, despite the danger of
misunderstanding and thus underestimating these thinkers because of
anachronism, there is an important sense in which it is quite
reasonable to refer to them as philosophers. That sense is inherent in
Aristotle's view (see, e.g., *Metaphysics* I,
*Physics* I, *De Anima* I, *On Generation and
Corruption* I): these thinkers were his predecessors in a
particular sort of inquiry, and even though Aristotle thinks that they
were all, for one reason or another, unsuccessful and even amateurish,
he sees in them a similarity such that he can trace a line of
continuity of both subject and method from their work to his own. The
questions that the early Greek philosophers asked, the sorts of
answers that they gave, and the views that they had of their own
inquiries were the foundation for the development of philosophy as it
came to be defined in the work of Plato and Aristotle and their
successors. Perhaps the fundamental characteristic is the commitment
to explain the world naturalistically, in terms of its own inherent
principles. (For discussions, see Sassi, 2006, 2018.)



By contrast, consider the 7th century BCE poem of Hesiod,
his *Theogony* (genealogy of the gods). Hesiod tells the
traditional story of the Olympian gods, beginning with Chaos, a vague
divine primordial entity or condition. From Chaos, a sequence of gods
is generated, often by sexual congress, but sometimes no cause for
their coming to be is given. The divine figures that thus arise are
often connected with a part of the physical universe, or with some
aspect of human experience, so his theogony is also a cosmogony (an
account of the generation of the world). The divinities (and the
associated parts of the world) come to be and struggle violently among
themselves; finally Zeus triumphs and establishes and maintains an
order of power among the others. Hesiod's world is one in which
the major divinities are individuals who behave like super-human
beings (Gaia or earth, Ouranos or sky, Cronos -- an unlocated
regal power, Zeus); some of the others are personified characteristics
(e.g., Momus, blame; and Dusnomia, lawlessness). For the Greeks, the
fundamental properties of divinity are immortality (they are not
subject to death) and great power (as part of the cosmos or in
managing events), and each of Hesiod's characters has these
properties (even though in the story some are defeated, and seem to be
destroyed). Hesiod's story is like a vast Hollywood-style family
history, with envy, rage, love, and lust all playing important parts
in the coming-to-be of the world as we know it. The earliest rulers of
the universe are violently overthrown by their offspring (Ouranos is
overthrown by Cronos, Cronos by Zeus). Zeus insures his continued
power by swallowing his first consort Metis (counsel or wisdom); by
this he prevents the predicted birth of rivals and acquires her
attribute of wisdom (*Theogony* 886-900). In a second
poem, *Works and Days*, Hesiod pays more attention to human
beings, telling the story of earlier, greater creatures who died out
or were destroyed by themselves or Zeus. Humans were created by Zeus,
are under his power, and are subject to his judgment and to divine
intervention for either good or ill. Hesiod's world, like
Homer's, is one that is god-saturated, where the gods may
intervene in all aspects of the world, from the weather to mundane
particulars of human life, acting on the ordinary world order, in a
way that humans, limited as they are by time, location, and narrow
powers of perception, must accept but cannot ultimately understand.
The Presocratics reject this account, instead seeing the world as a
*kosmos*, an ordered natural arrangement that is inherently
intelligible and not subject to supra-natural intervention. A striking
example is Xenophanes DK21B32/LM8D9: "And she whom they call
Iris, this too is by nature cloud / purple, red, and greeny yellow to
behold." Iris, the rainbow, traditional messenger of the gods,
is after all, not supra-natural, not a sign from the gods on Olympus
who are outside of and immune from the usual world order; rather it
is, in its essence, colored cloud. (A good discussion of the Hesiodic
myths in relation to Presocratic philosophy can be found in McKirahan
2011. Burkert 2008 surveys influence from the east on the development
of Presocratic philosophy, especially the myths, astronomy, and
cosmogony of the Babylonians, Persians, and Egyptians.)



Calling the Presocratics *philosophers* also suggests that they
share a certain outlook; an outlook that can be contrasted with that
of other early Greeks (see Moore 2020). Although scholars disagree
about the extent of the divergence between the early Greek
philosophers and their non-philosophical predecessors and
contemporaries, it is evident that Presocratic thought exhibits a
difference not only in its understanding of the nature of the world,
but also in its view of the sort of explanation of it that is
possible. This is clear in Heraclitus. Although Heraclitus asserts
that those who love wisdom must be inquirers into many things, inquiry
alone is not sufficient. At DK22B40/LMD20 he rebukes four of his
predecessors: "Much learning does not teach understanding; else
it would have taught Hesiod and Pythagoras, and again Xenophanes and
Hecataeus." Heraclitus' implicit contrast is with himself;
in DK 22B1/LM D9 and D110 he suggests that he alone truly understands
all things, because he grasps the account that enables him to
"distinguish each thing in accordance with its nature" and
say how it is. For Heraclitus there is an underlying principle that
unites and explains everything. It is this that others have failed to
see and understand. According to Heraclitus, the four have amassed a
great deal of information -- Hesiod was a traditional source of
information about the gods, Pythagoras was renowned for his learning
and especially views about how one ought to live, Xenophanes taught
about the proper view of the gods and the natural world, Hecataeus was
an early historian -- but because they have failed to grasp the
deeper significance of the facts available to them, their unconnected
bits of knowledge do not constitute understanding. Just as the world
is a *kosmos*, an ordered arrangement, so too, human knowledge
of that world must be ordered in a corresponding way.


## 2. The Milesians



In his account of his predecessors' searches for "causes
and principles" of the natural world and natural phenomena,
Aristotle says that Thales of Miletus (a city in Ionia, on the west
coast of what is now Turkey) was the first to engage in such inquiry.
He seems to have lived around the beginning of the 6th c.
BCE. Aristotle mentions that some people, before Thales, placed great
importance on water, but he credits Thales with declaring water to be
the first cause (*Metaphysics* 983b27-33), and he then
later raises the question of whether perhaps Hesiod was the first to
look for a cause of motion and change (984b23ff.). These suggestions
are rhetorical: Aristotle does not seriously imply that those he
mentions are engaged in the same sort of inquiry as he thinks Thales
was. Two other Greek thinkers from this very early period, Anaximander
and Anaximenes, were also from Miletus, and although the ancient
tradition that the three were related as master and pupil may not be
correct, there are enough fundamental similarities in their views to
justify treating them together. 



The tradition claims that Thales predicted a solar eclipse in 585 BC
(DK 11A5/LM 5P9, P10), introduced geometry into Greece from Egypt (DK
11A11/LM 5P4, P5, R11), and produced some engineering marvels.
Anaximander is reported to have invented the gnomon (the raised piece
of a sundial whose shadow marks time); to have created a sphere of the
heavens serving as an astronomical and cosmological model (DK 12A1/LM
6P2, P4, P11); and to have been the first to draw a map of the
inhabited world (DK 12A6/LM 6P6, D4). Regardless of whether these
reports are correct (and in the case of Thales' prediction they
almost certainly are not), they indicate something important about the
Milesians: their interests in measuring and explaining celestial and
terrestrial phenomena were as strong as their concern with the more
abstract inquiries into the causes and principles of substance and
change attributed to them by Aristotle (Algra 1999, White 2002 and
2008). They did not see so-called "scientific" and
"philosophical" questions as belonging to separate
disciplines, requiring distinct methods of inquiry. The assumptions
and principles that we (along with Aristotle) see as constituting the
philosophical foundations of their theories are, for the most part,
implicit in the claims that they make. Nevertheless, it is legitimate
to treat the Milesians as having philosophical views, even though no
clear statements of these views or specific arguments for them can be
found in the surviving fragments and testimonia. 



Aristotle's comments do not sound as if they were based on
first-hand knowledge of Thales' views, and the doxographical
reports say that Thales did not write a book. Yet Aristotle is
confident that Thales belongs, even if honorifically, to that group of
thinkers that he calls "inquirers into nature" and
distinguishes him from earlier poetical "myth-makers." In
Book I of *Metaphysics*, Aristotle claims that the earliest
of these, among whom he places the Milesians, explained things only in
terms of their matter (*Met*. I.3 983b6-18). This claim
is anachronistic in that it presupposes Aristotle's own novel
view that a complete explanation must encompass four factors: what he
called the material, efficient, formal, and final causes. Yet there is
something in what Aristotle says. Aristotle links Thales' claim
that the world rests on water with the view that water was the
*arche*, or fundamental principle, and he adds that
"that from which they come to be is a principle of all
things" (983b24-25; DK 11A12/LM 5D3, R9). He suggests that
Thales chose water because of its fundamental role in coming-to-be,
nutrition, and growth, and claims that water is the origin of the
nature of moist things. 



Aristotle's general assertion about the first thinkers who gave
accounts of nature (and his specific discussion of Thales'
reliance on water as a first principle) brings out a difficulty in
interpreting the early Presocratics. According to Aristotle's
general account, the Presocratics claimed that there was a single
enduring material stuff that is both the origin of all things and
their continuing nature. Thus, on this view, when Thales says that the
first principle is water, he should be understood as claiming both
that the original state of things was water and that even now (despite
appearances), everything is really water in some state or another. The
change from the original state to the present one involves changes in
the material stuff such that although it may not now appear to be
water everywhere (but seems to be airier or earthier than water in its
usual state, or its original one), there is no transformation of water
into a different kind of stuff (air or earth, for instance). Yet, when
Aristotle comes to give what details he can of Thales' view, he
suggests only that for Thales, water was the first principle because
everything comes from water. Water, then, was perhaps the original
state of things for Thales, and water is a necessary condition for
everything that is generated naturally, but Aristotle's summary
of Thales' view does not imply that Thales claimed that water
endures through whatever changes have occurred since the original
state, and now just has some new or additional properties. Thales may
well have thought that certain characteristics of the original water
persisted: in particular its capacity for motion (which must have been
innate in order to generate the changes from the original state). This
is suggested by Thales' reported claims that the lodestone (with
its magnetic properties) and amber (which when rubbed exhibits powers
of attraction through static electricity) have souls and that all
things are full of gods. Aristotle surmises that Thales identified
soul (that which makes a thing alive and thus capable of motion) with
something in the whole universe, and so supposed that everything was
full of gods (DK11A22/LM5D10, D11a )--water, or soul, being a
divine natural principle. Certainly the claim that the lodestone has
soul suggests this account. Given that the analysis of change (both
qualitative and substantial) in terms of a substratum that gains and
loses properties is Aristotelian (although perhaps foreshadowed in
Plato), it is not surprising that the earlier views were unclear on
this issue, and it is probable that the Milesian view did not clearly
distinguish the notions of an original matter and an enduring
underlying stuff (Graham 2006). 



The reports about Thales show him employing a certain kind of
explanation: ultimately the explanation of why things are as they are
is grounded in water as the basic stuff of the universe and the
changes that it undergoes through its own inherent nature. In this,
Thales marks a radical change from all other previous sorts of
accounts of the world (both Greek and non-Greek). Like the other
Presocratics, Thales sees nature as a complete and self-ordering
system, and sees no reason to call on divine intervention from outside
the natural world to supplement his account--water itself may be
divine, but it is not something that intervenes in the natural world
from outside (Gregory, 2013). While the evidence for Thales'
naturalistic account is circumstantial, this attitude can be directly
verified for Anaximander. 



In the one fragment that can be securely attributed to Anaximander
(although the extent of the implied quotation is uncertain), he
emphasizes the orderly nature of the universe, and indicates that the
order is internal rather than imposed from outside. Simplicius, a
6th c. CE commentator on Aristotle's
*Physics*, writes: 



> 
> Of those who say that [the first principle] is one and moving and
> indefinite, Anaximander, son of Praxiades, a Milesian who became
> successor and pupil to Thales, said that the indefinite (*to
> apeiron*) is both principle (*arche*) and element
> (*stoicheion*) of the things that are, and he was the first to
> introduce this name of the principle. He says that it is neither water
> nor any other of the so-called elements, but some other indefinite
> (*apeiron*) nature, from which come to be all the heavens and
> the worlds in them; and those things, from which there is coming-to-be
> for the things that are, are also those into which is their
> passing-away, in accordance with what must be. For they give penalty
> (*dike*) and recompense to one another for their
> injustice (*adikia*) in accordance with the ordering of
> time--speaking of them in rather poetical terms. It is clear that
> having seen the change of the four elements into each other, he did
> not think it fit to make some one of these underlying subject, but
> something else, apart from these. (Simplicius, *Commentary on
> Aristotle's Physics* 24, lines 13ff. = DK12A9/LM6P5, D6, D12
> and
>  DKB1/LM6D6)[1]
> 



Thus, there is an original (and originating) indefinite stuff, from
which all the heavens and the worlds in them come to be. This claim
probably means that the original state of the universe was an
indefinitely large mass of stuff that was also indefinite in its
 character.[2]
 This stuff then gave rise through its own inherent power to the
ingredients that themselves constitute the world as we perceive it.




A testimony about Anaximander from Pseudo-Plutarch (DK12A10/LM6P6, D4)
says that "Something productive of hot and cold was separated
off from the eternal at the genesis of this world and from this a
sphere of flame grew around the air around the earth like the bark
around a tree." Neither the cause nor the precise process of
separation is explained, but it is probable that Anaximander would
have thought of motion as innate and so that the original source of
change was part of the character of the indefinite itself. The passage
from Simplicius shows that Anaximander does not think that the eternal
indefinite stuff gives rise directly to the cosmos as we know it.
Rather, relying on a semi-biological model, Anaximander claims that
the *apeiron* somehow generates the opposites hot and cold. Hot
and cold are themselves stuffs with powers; and it is the actions of
these stuffs/powers that produce the things that come to be in our
world. The opposites act on, dominate, and contain each other,
producing a regulated structure; thus things pass away into those
things from which they came to be. It is this structured arrangement
that Anaximander refers to when he speaks of justice and reparation.
Over the course of time, the cycles of the seasons, the rotations of
the heavens, and other sorts of cyclical change (including
coming-to-be and passing-away) are regulated and thus form a system.
This system, ruled by the justice of the ordering of time is in sharp
contrast with the chaotic and capricious world of the personified
Greek gods who interfere in the workings of the heavens and in the
affairs of human beings (Kahn 1985a, Vlastos 1947, Guthrie 1962). 



The pattern that can be seen in Thales and Anaximander of an original
stuff giving rise to the phenomena of the cosmos continues in the
views of the third of the Milesians, Anaximenes. He replaces
Anaximander's *apeiron* with air, thus eliminating the
first stage of the coming-to-be of the cosmos (the something
productive of hot and cold). Rather, he returns to an originating
stuff more like Thales' water. In DK13A5/LM7D1 and D7
Aristotle's associate Theophrastus, quoted by Simplicius,
speculates that Anaximenes chose air because he agreed that a basic
principle must be neutral (as Anaximander's *apeiron* is)
but not so lacking in properties that it seems to be nothing at all.
Air can apparently take on various properties of color, temperature,
humidity, motion, taste, and smell. Moreover, according to
Theophrastus, Anaximenes explicitly states the natural mechanism for
change; it is the condensation and rarefaction of air that naturally
determine the particular characters of the things produced from the
originating stuff. Rarified, air becomes fire; more and more
condensed, it becomes progressively wind, cloud, water, earth, and
finally stones. "The rest," says Theophrastus, "come
to be from these." Plutarch says that condensation and
rarefaction are connected with cooling and heating, and he gives the
example of breath (DK13B1/LM7D8,R4). Releasing air from the mouth with
compressed lips produces cool air (as in cooling soup by blowing on
it), but relaxed lips produce warm air (as when one blows on cold
hands to warm them up). 



Does the originating stuff persist through the changes that it
undergoes in the generating processes? Aristotle's account
suggests that it does, that Anaximenes, for instance, would have
thought that stone was really air, although in an altered state, just
as we might say that ice is really water, cooled to a point where it
goes from a liquid to a solid state. Because the water does not cease
to be water when it is cooled and becomes ice, it can return to a
liquid when heated and then become a gas when more heat is applied. On
this view, the Milesians were material monists, committed to the
reality of a single material stuff that undergoes many alterations but
persists through the changes (Barnes 1979, Guthrie 1962, Sedley 2007
and 2009). Yet there are reasons to doubt that this was actually the
Milesian view. It presumes that the early Greek thinkers anticipated
Aristotle's general theory that change requires enduring
underlying substances that gain and lose properties. The earliest
Greeks thought more in terms of powers (Vlastos 1947, Heidel 1906),
and the metaphysical problem of what it is to be a substance was yet
to be formulated. Clearly the Milesians were interested in the
originating stuff from which the world developed (Anaximander and
Anaximenes are explicit about transformations of such an eternal
originating stuff), but the view that this endured as a single
substratum may not have been theirs. Rather, it has been suggested by
Graham (1997 and 2006; Mourelatos 2008) that the Milesians were not,
in Aristotle's sense, material monists. On this view, the
original/originating stuff is transformed into other substances.
Anaximenes, for instance, may have thought that the change from air to
water does not involve the persistence of air as any sort of
substratum. There is no special role that air plays in the theory
except that it is the originating stuff and so first in an analysis of
the law-like cyclical changes that produce various stuffs as the
cosmos develops (Graham 2006, ch. 4). Such an interpretation suggests
how different the Milesian conception of the world is from
Aristotle's.


## 3. Xenophanes of Colophon and Heraclitus of Ephesus



Living in the last years of the 6th c. and the beginning of
the 5th, Xenophanes and Heraclitus continue the Milesian
interest in the nature of the physical world, and both offer
cosmological accounts; yet they go further than the Milesians not only
through their focus on the human subject and the expanded range of
their physical explanations, but by investigating the nature of
inquiry itself. Both explore the possibility of human understanding
and question its limits. Recent work on Xenophanes' epistemology
and his cosmology has made much of his scientific work clearer and
more impressive (Lesher 1992, Mourelatos 2008). He has, to a great
extent, been rescued from his traditional status as a minor traveling
poet-sage who railed against the glorification of athletes and made
some interesting comments about the relativity of human conceptions of
the gods. Instead, he has come to be seen as an original thinker in
his own right who influenced later philosophers trying to characterize
the realms of the human and the divine, and exploring the possibility
that human beings can gain genuine knowledge and wisdom, i.e., are
able to have a god's eye view of things and understand them
(Curd 2013, Mogyorodi 2002 and 2006). 



Xenophanes claims that all meteorological phenomena are clouds,
colored, moving, incandescent: rainbow, St. Elmo's Fire, the
sun, the moon. Clouds are fed by exhalations from the land and sea
(mixtures of earth and water). The motions of earth and water, and
hence of clouds, account for all the things we find around us. His
explanations of meteorological and heavenly phenomena lead to a
naturalistic science:



> 
> 
> She whom they call Iris, this too is by nature (*pephuke*)
> cloud
>   
> 
> purple, and red, and greeny-yellow to behold. (DK21B32/LM8D39)
> 
> 
> 
> Xenophanes says that the star-like phenomena seen when aboard ship,
> which some call the Dioscuri, are cloudlets, glimmering because of
> their kind of motion. (DkA39/LM8D38)
> 
> 
> 



In the 1980's Alexander Mourelatos argued that Xenophanes
employs an important new pattern of explanation: *X* is really
*Y*, where *Y* reveals the true character of *X*.
Xenophanes signals this by the use of *pephuke* in
DK21B32/LM8D39, and no doubt it (or some word like it) was there in
the original of DKA39/LMD36 as well. Xenophanes thus provides an
account of a phenomenon often taken to be a sign from the
divine--Iris as the messenger; the Dioscuri (St. Elmo's
fire) as comfort for sailors--that reduces it to a natural
occurrence. 



That meteorological phenomena are not divine is not all that
Xenophanes has to say about the gods. He notes anthropomorphic
tendencies in conceptions of the gods (DKB14/LMD12: "Mortals
suppose that the gods are born, and have their own dress, voice, and
body;" DKB16/LMD13: "Ethiopians say that their gods are
snub-nosed and dark, Thracians, that theirs are grey-eyed and
red-haired"). He also famously suggests that horses, oxen, and
lions would have equine, bovine, and leonine gods (DKB15/LM14). Yet
Xenophanes also makes positive claims about the nature of the divine,
including the claim that there is a single greatest god:



> 
> One god greatest among gods and men,
>   
> 
> Resembling mortals neither in body nor in thought.
>   
> 
> ... whole [he] sees, whole [he] thinks, and whole [he] hears,
>   
> 
> but completely without toil he agitates all things by the
>   
> 
>    thought of his mind.
>   
> 
> ... always he remains in the same (state), agitated not at all,
>   
> 
> nor is it fitting that he come and go to different places at different
> times. (DK B23, B24, B25, B26 / LM D16, 17, 18, 19)
> 



While indifferent to the affairs of human beings, Xenophanes'
divine being comprehends and controls a cosmos that is infused with
thinking: it is understood, organized, and managed by divine
intellection. Having removed the gods as bearers of knowledge to
humans, and denied that the divine takes an active interest in what
mortals can or cannot know, Xenophanes asserts the conclusion to be
drawn from his naturalistic interpretation of phenomena: the gods are
not going to reveal anything to us; we are epistemologically
autonomous and must rely on our own capacity for inquiry. That way, we
"discover better," as he says in DKB18/LMD53, a fragment
that is optimistic about the capacities of human intelligence (see
Lesher 1991):



> 
> Indeed not even from the beginning did the gods indicate all things to
> mortals, but, in time, inquiring, they discover better.
> 



This suggests that human thought can mimic divine understanding, at
least to some degree. Xenophanes' own practice seems consistent
with the claims of DKB18/LMD53; his own inquiries and explanations led
him to unified explanations of terrestrial and celestial phenomena.
Yet DKB34/LMD49 suggests skepticism: 



> 
> And of course the clear and certain truth no man has seen,
>   
> 
> nor will there be anyone who knows about the gods and what I say about
> all things;
>   
> 
> for even if, in the best case, he should chance to speak what is the
> case,
>   
> 
> all the same, he himself does not know; but opinion is found over all.
> 



Whether this is global or limited skepticism is controversial (Lesher
1992 and 1994 argues for a limited interpretation). Xenophanes
stresses the difficulty of coming to certainty, particularly about
things beyond our direct experience. Nonetheless, in DKB35/LMD50 (a
tantalizingly short fragment), Xenophanes says, "Let these thing
be accepted to be like the truth" (see Bryan 2012 for a full
discussion).



Famously obscure, accused by Plato of incoherence and by Aristotle of
denying the law of non-contradiction, Heraclitus writes in an
aphoristic style. His apparently paradoxical claims present
difficulties to any interpreter. Nevertheless, he raises important
questions about knowledge and the nature of the world. The opening of
Heraclitus' book refers to a "*logos* which holds
 forever."[3]
 There is disagreement about exactly what Heraclitus meant by using
the term *logos*, but it is clear from DK22B1/LM9D1, D110, and
R86 and DKB2/LM9D2 as well as DKB50/LMD46 and other fragments that he
refers to an objective law-like principle that governs the cosmos, and
which it is possible (but difficult) for humans to come to understand.
There is a single order that directs all things ("all things are
one" DKB50/LMD46); this order is divine, and is sometimes
connected by humans with the traditional gods (it is "both
unwilling and willing to be called by the name of Zeus"
DKB32/LMD45). Just as Zeus, in the traditional view, controls
everything from Olympus with a thunderbolt, so this single ordered
system also steers and controls the whole cosmos, but from within. The
sign of the unchanging order of the eternal system is fire--just
as fire is always changing and always the same, the *logos*,
itself permanent, contains the unchanging account that explains the
alterations and transformations of the cosmos.



This plan or order that steers the cosmos is, itself, a rational
order. This means not only that it is non-capricious and so
intelligible (in the sense that humans can, at least in principle,
come to understand it), it is also an intelligent system: there is an
intelligent plan at work, if only in the sense of the cosmos working
itself out in accordance with rational
 principles.[4]
 Consider DKB114/LMD105:



> 
> Those who would speak with understanding must ground themselves firmly
> in that which is common to all, just as a city does in its law, and
> even more firmly! For all human laws are nourished by one law, the
> divine; for it rules as far at it wishes and suffices for all, and is
> still more than enough.
> 



Heraclitus is not only claiming that human prescriptive law must
harmonize with divine law, but he is also asserting that divine law
encompasses both the universal laws of the cosmos itself and the
particular laws of humans. The cosmos itself is an intelligent,
eternal (and hence divine) system that orders and regulates itself in
an intelligent way: the *logos* is the account of this
self-regulation. We can come to grasp and understand at least part of
this divine system. This is not merely because we ourselves are part
of (contained in) the system, but because we have, through our
capacity for intelligent thinking, the power to grasp the system as a
whole, through knowing the *logos*. How this grasping is
supposed to work is tantalizingly obscure. 



Heraclitus regards the cosmos as an ordered system like a language
that can be read or heard and understood by those who are attuned to
it. That language is not just the physical evidence around us
("Eyes and ears are bad witnesses to those with barbarian
souls" DKB107/LMD33); the sheer accumulation of information is
not the same as wisdom (see the rebuke in DK22B40/LMD20, quoted
above). Although the evidence of the senses is important (see
DKB55/LMD31),
careful and thoughtful inquiry is also necessary. Those who are lovers
of wisdom must be good inquirers into many things (DKB35/LMD40; also
DKB101/LM36: "I enquired into myself") and must be able to
grasp how the phenomena are signs or evidence of the larger order; as
Heraclitus notes in DKB123/LMD35, "nature is accustomed to hide
itself," and the evidence must be interpreted carefully. That
evidence is the interplay of opposing states and forces, which
Heraclitus points to by claims about the unity of opposites and the
roles of strife in human life as well as in the cosmos. There are
fragments that proclaim the unity or identity of opposites: the road
up and down are one and the same (DKB60/LMD51), the path of writing is
both straight and crooked (DKB59/LMD52), sea water is very pure and
very foul (DKB61/LMD78). The famous river fragments (DKB49a/LMR9;
DKB12/LMD65a, D102; DKB91a not in LM) question the identity of things
over time, while a number of fragments point to the relativity of
value judgments (DKB9, B82, B102 / LM D79, D81, D73).
Anaximander's orderly arrangement of just reciprocity governed
by time is replaced by a system ruled by what Heraclitus calls war:
"It is right to know that war is common and justice strife, and
that all things come to be through strife and are so ordained"
(DKB80/LMD63). This strife or war is the set of changes and
alterations that constitute the processes of the cosmos. These changes
are regular and capable of being understood by one who can speak the
language of the *logos* and thus interpret it properly (see
Long 2009). Although the evidence is confusing, it points to the
deeper regularities that constitute the cosmos, just as
Heraclitus' own remarks can seem obscure yet point to the truth.
Heraclitus surely has his own message (and his delivery of it) in mind
in DKB93/LM41, "The lord whose oracle is at Delphi neither
speaks nor conceals, but gives a sign." 



One of the earliest of the Greek philosophers to discuss the human
soul, Heraclitus' claims about it, like his other views, are
expressed enigmatically. Yet it seems fairly clear that he treats soul
as the seat of emotion, movement, and intellect. DKB107/LMD33 (quoted
above) indicates that understanding is a function of soul, and in
DKB117/LMD104, the drunken man who must be led by a boy because he has
lost control of his legs, and does not know where he goes or what he
does. Drunkenness is the cause of all this: because his soul has
become wet its powers are dampened down and become ineffective.
DKB118/LMD103 asserts "gleam of light: dry soul, wisest and
best" (there is some uncertainty about the text). This suggests
that for Heraclitus, soul is a stuff that is affected by changes along
the hot/cold and wet/dry continua and that the a fiery, i.e., hotter
soul is best. Indeed in DKB36/LMD100, soul is listed as one of the
stages of transformation of the cosmic stuffs: "it is death to
souls to become water, and to water death to become earth; from earth
water comes to be, from from water, soul." Although Heraclitus
says that it is only divine nature that has complete understanding
(DKB78/LMD74), his linking of fire with the *logos* and the
divine, along with his view that the best and wisest soul is hot and
dry, suggests that humans who care for their souls and search for the
truth contained in the
*logos* can overcome human ignorance and approach the
understanding that Heraclitus himself has obtained. (Betegh 2007,
2009, 2013b and Dilcher 1995 discuss the nature and importance of soul
for Heraclitus; see also Granger 2000 and Kahn 1979.)


## 4. Parmenides of Elea



Parmenides, born ca. 510 BCE in the Greek colony of Elea in southern
Italy (south of Naples, and now known as Velia), explores the nature
of philosophical inquiry, concentrating less on the contents of knowledge or
understanding (although he has views about these) than on what sort of thing can be
understood. Xenophanes identified genuine knowledge with the grasping
of the sure and certain truth and claimed that "no man has
seen" it, at least with respect to some topics (DK21B34/LM8D49);
Heraclitus had asserted that divine nature, not human, has right
understanding (DK22B78/LM9D74), although he implies that some humans
can acquire divine-like understanding. Parmenides argues that human
thought can reach genuine knowledge or understanding, and that there
are certain marks or signs that act as guarantees that the goal of
knowledge has been reached. A fundamental part of Parmenides'
claim is that what *must* be (cannot not-be, as Parmenides puts
it) is more knowable than what is merely contingent (what may or may
not be), which can be the object only of belief. 



Parmenides gives us a poem in Homeric hexameters, narrating the
journey of a young man (a *kouros*, in Greek) who is taken to
meet a goddess who promises to teach him "all things"
(DK28B1/LM19D4). The content of the story the goddess tells is not the
knowledge that will allow humans, by having it, to know. Rather, the
goddess gives the *kouros* the tools to acquire that knowledge
himself:



> 
> It is right that you learn all things,
>   
> 
> Both the unshaking heart of well-persuasive truth,
>   
> 
> and the beliefs of mortals, in which there is no true trust.
>   
> 
> But nevertheless, you shall learn these things too, how it were right
> that the things that seem be reliably, being indeed the whole of
> things. (DKB1.28-32/LMD4.28-32; the last two lines text are uncertain.)
> 



The goddess does not provide the *kouros* with a list of true
propositions, as a body of knowledge for him to acquire, and false
ones to be avoided. Rather, in teaching him how to evaluate claims
about what-is, the goddess unleashes the *kouros'* own
cognitive powers to know everything, by testing and evaluation,
accepting or rejecting claims about the ultimate nature of
things-- for that alone is capable of being known. For
Parmenides, the mark of what is known is that it is something that
genuinely is, with no taint of what-is-not. That is why, for him,
what-is not only is, but must be and cannot not-be. He sets this out
in the key passages of DKB2 and
 B3/LM19D6:[5]



> 
> Come now, and I will tell you, and you, hearing, preserve the story,
>   
> 
> the only routes of inquiry there are for thinking;
>   
> 
> the one that it is and that it cannot not be
>   
> 
> is the path of Persuasion (for it attends upon truth)
>   
> 
> the other, that it is not and that it is right that it not be,
>   
> 
> this I point out to you is a path wholly inscrutable
>   
> 
> for you could not know what is not (for it is not to be accomplished)
>   
> 
> nor could you point it out... For the same thing is for thinking
> and for being.
> 



The routes are methods of inquiry: keeping on the correct route will
bring one to what-is, the real object of thought and understanding.
Although what the goddess tells the *kouros* has divine
sanction (hers), that is not why he should accept it. Rather, the
truth she tells reveals a mark of its own truth: it is testable by
reason or thought itself. In DKB7/LMD8 the goddess warns that we must
control our thought in the face of the ever-present seductions of
sense-experience:



> 
> For never shall this be forced through: that things that are not are;
>   
> 
> but restrain your thought from this route of inquiry,
>   
> 
> nor let much-experienced habit force you along this path,
>   
> 
> to ply an aimless eye and resounding ear
>   
> 
> and tongue, but judge by reasoning (*logos*) the much-battled
> testing
>   
> 
> spoken by me.
> 



The *kouros* himself can reach a decision or determination of
the truth solely through use of his *logos*. *Logos*
here means thinking or reasoning (Parmenides probably means the human
capacity for thought in general). The test (restated at
B8.15-16/LMD8.20-21, is "is or is not?" This
is not just a question of non-contradiction (which would give us
coherence), but an inquiry whether or not the supposition that
something is would entail, on further examination, the reality of
what-is-not (which is impossible). 



The arguments of DKB8/LMD8 demonstrate *how* what-is must be.
In applying these arguments as tests against any suggested basic
entity in the Presocratic search for ultimate causes or principles,
the *kouros* can determine whether or not a proposed theory is
acceptable. For Parmenides *noos* is not itself an infallible
capacity. One can think well or badly; correct thinking is that which
takes the correct route and so reaches what-is. The mortals on the
incorrect route are thinking, but their thoughts have no real object
(none that is real in the appropriate way), and so cannot be completed
or perfected by reaching the truth. In B8 Parmenides sets out the
criteria for the being of what-is, and then the arguments for those
criteria:



> 
> ... a single account still
>   
> 
> remains of the route that it is; and on this route there are
>   
> 
> very many signs, that what-is is ungenerable and imperishable,
>   
> 
> a whole of a single kind, and unshaking and complete;
>   
> 
> nor was it nor will it be, since it is now all together
>   
> 
> one, cohesive. (DKB8.1-6/LMD8.6-11)
> 



Any thing that genuinely is cannot be subject to coming-to-be or
passing-away, must be of a single nature, and must be complete, in the
sense of being unchangeably and unalterably what it is. These are
signs for what any ultimate cause or principle must be like, if it is
to be satisfactory as a principle, as something that can be known. The
signs are adverbial, showing how what-is is (Mourelatos 2008). Only an
entity which is in the complete way can be grasped and understood in
its entirety by thought. McKirahan (2008) provides a thorough analysis
of the arguments of DKB8/LMD8, as do Palmer (2009) and Graham
(2010).



After laying out the arguments about what-is, the goddess turns to the
route of mortals, in an account which she calls
"deceptive." Although Parmenides has been read as thus
rejecting any possibility of cosmological inquiry (Barnes 1979, Owen
1960), there are forceful interpretations that allow for justified
belief about the contingent world, a world that may or may not be, and
is not such that it must be (Nehamas 2002, Curd 2004, Palmer 2009).
The problem of mortals is that they mistake what they perceive for
what there is (and must be). As long as one realizes that the world of
perception is not genuinely real, and cannot therefore be the object
of knowledge, it may be possible for there to be justified belief
about the cosmos. Some details of Parmenides' own cosmology are
given, arguably as justified belief, in the *Doxa* section of
the poem, and more in the testimonia from later authors. Parmenides
seems to have been the first Presocratic to claim that the moon gets
its light from from the sun and that the earth is spherical. Recently
scholars have focused on these claims about the natural world, and
have argued that Parmenides should be understood as offering an
account of appearances that can and should be deemed acceptable
(Palmer 2009, Cordero 2010, Graham 2013, Mourelatos 2013, Bryan 2012,
Johansen 2016). Nevertheless, Parmenides marks a sharp distinction
between being (what-is and must be) and becoming, and between
knowledge and perception-based belief or opinion.


## 5. The Pythagorean Tradition



In the last quarter of the sixth century, before Parmenides'
birth, Pythagoras of Samos (an Aegean island) arrived in Croton, in
southern Italy. He established a community of followers who adopted
his political views, which favored rule by the "better
people," and also the way of life he recommended on what seem to
have been more or less philosophical bases. The traditional view has
been that the aristocracy, the "better people," generally
meant the rich. But Burkert notes that as early as the 4th
c. BCE there were two traditions about Pythagoras, one that meshes
with the traditional view and associates Pythagoras with political
tyrants, and another that credits him with rejecting tyrannies for
aristocracies that might not have been grounded in wealth (Burkert
1972, 119). The Pythagorean Archytas (born late 5th
century) lived in a democracy (Tarentum in southern Italy), and seems
to have argued for fair and proportionate dealings between rich and
poor (Huffman 2005). The Pythagorean way of life included adherence to
certain prescriptions including religious rites and dietary
restrictions (there is a general discussion in Kahn 2001). Detailed
treatment of Pythagoras and Pythagoreanism can be found in Zhmud (2012
and 2013); an excellent collection of articles on Pythagoreanism is in
Huffman (ed.) 2014. 



Like Socrates, Pythagoras wrote nothing himself, but had a great
influence on those who followed him. He had a reputation for great
learning and wisdom (see Empedocles DKD31B129/LM22.D38, R43), although
he was treated satirically by both Xenophanes (DK21B7/LM8.D64) and
Heraclitus (DK22B40/LM9D20, DKB129/LMD26). We do not know to what
extent this included knowledge of mathematics, as would be suggested
by the attribution to him of the famous Pythagorean theorem of
geometry (Rowett 2013). The details of Pythagoras' views are
unclear, but he seems to have advocated the reincarnation of the soul
(a novel idea among the Greeks, also developed in Orphic religion) and
the possibility of the transmigration of the human soul after death
into other animal forms. Pythagorean writers after his own time
stressed the mathematical structure and order of the universe. This is
often attributed directly to Pythagoras, but recent scholarship has
shown that the evidence for attributing this mathematically-based
cosmology to Pythagoras himself is convoluted and doubtful (Burkert
1972, Huffman 1993 and 2005; but see Zhmud 1997). 



What seems clear is that the early Pythagoreans conceived of nature as
a structured system ordered by number (see the entry on
 Pythagoras), and that such 
post-Parmenidean Pythagoreans as Philolaus
(last half of the 5th century, more than a generation after
Pythagoras' death) and Archytas (late 5th to early
4th century) held more complicated views about the relation
between mathematics and cosmology than it is reasonable to suppose
Pythagoras himself could have advanced. The Pythagorean tradition thus
includes two strains. There are reports of a split in the period after
Pythagoras' death between what we would term the more
philosophically inclined Pythagoreans and others who primarily adopted
the Pythagorean ethical, religious and political attitudes. The
latter, called the *acusmatici*, followed the Pythagorean
precepts, or *acusmata* (which means "things
heard"). The former, the philosophical Pythagoreans (including
Philolaus and Archytas), were the so-called *mathematici*, and
while they recognized that the *acusmatici* were indeed
Pythagoreans by virtue of accepting Pythagorean precepts, they claimed
that they themselves were the true followers of Pythagoras.



Philolaus of Croton seems to have blended the Pythagorean life with an
awareness of and appreciation for the arguments of Parmenides (Huffman
1993). According to Philolaus, "Nature in the cosmos was fitted
together out of unlimiteds and limiters" (DK44B1/LM12D2). These
limiters and unlimiteds play the role of Parmenidean basic
realities--they are and unchangingly must be what they are, and
so can be known; they are joined together in a harmonia (literally, a
carpenter's joint; metaphorically, a harmony), and "it was
not possible for any of the things that are and are known by us to
come to be, without the existence of the being of things from which
the cosmos was put together" (DK44B6/LM12D5, D14). The
unlimiteds are unstructured stuffs and continua; the limiters impose
structure (shape, form, mathematical structure) on the unlimiteds.
Things become knowable because they are structured in this way; the
structure can apparently be expressed in a numerical ratio that allows
for understanding: "All things that are known have number; for
without this nothing whatever could possibly be thought of or
known" (DK44B4/LMD7). Philolaus also developed a theory of the
cosmos that displaced the earth from the center, replaced by what he
called Hestia, the central fire (Graham 2013, 2014), and offered novel
accounts of eclipses. 


## 6. Other Eleatics: Zeno and Melissus



Parmenides had argued that there were strict metaphysical requirements
on any object of knowledge; the later Eleatics (named for following
Parmenidean doctrines rather than for strictly geographical reasons),
Zeno of Elea (born ca. 490) and Melissus of Samos (fl. ca. 440),
extended and explored the consequences of his arguments. Zeno paid
particular attention to the contrast between the requirements of
logical argument and the evidence of the senses (Vlastos 1967 is a
masterly treatment of Zeno; see also McKirahan 1999 and 2005). The
four famous paradoxes of motion, for which he is now and in antiquity
best known, purported to show that, despite the evidence all around
us, the ordinary motion of everyday experience is impossible. The
paradoxes claim that motions can never be begun (the Achilles) or be
completed (the Dichotomy), entail contradictions (the Moving Blocks),
or are altogether impossible (the
 Arrow).[6]
 Recent philosophers of space and time (see Grunbaum 1967,
articles in Salmon 2001, Huggett 1999, and the entry on 
 Zeno's Paradoxes) hold that
 the arguments are reductios of the theses that
space and time are continuous (the Achilles and the Dichotomy) or
discrete (the Moving Blocks and the Arrow). Consider the Dichotomy: a
runner can never complete a run from point A to point B. First, the
runner must move from A to a point halfway between A and B (call it
C). But between A and C there is yet another halfway point (D), and
the runner must first reach D. But between A and D there is yet
another halfway point ... and so on, ad infinitum. So the runner,
starting at A, can never reach B. The argument assumes that it is
impossible to pass an infinite number of points in a finite time.
Similarly, Zeno produced paradoxes showing that plurality is
impossible: if things are many, contradictions follow (Plato's
*Parmenides* 127e1ff.; Zeno in DK29B1/LM20D5, D6;
DK29B2/LM20D7, R6; and DK29B3/LM20D11); there were also purported
proofs that place is impossible (DK29A24/LM20D13a, R22, R23) and that
things cannot have parts (the Millet Seed, DK29A29/LM20D12a, D12b,
R16).



Melissus, dismissed as a simple-minded thinker by Aristotle (and by
some contemporary scholars as well but see Makin 2005), expands
Parmenides' arguments about the nature of what-is (Palmer 2004).
It is Melissus who explicitly claims that only one thing can be: if
what-is is unlimited (as he thinks it is), it must be one and all
alike (if there were two [in number or in character] they would be
"limited against each other" DK30B6/LM21D6). Melissus
specifically argues against the empty (the void), and rejects the
possibility of rearrangement (which would allow for the appearance of
coming-to-be and passing-away, and of movement)--all these
characteristics are incompatible with the unity of what-is (i.e., the
One). Melissus thus claims that what is real is completely unlike the
world that we experience: the split between appearance and reality is
complete and unbridgeable.


## 7. The Pluralists: Anaxagoras of Clazomenae and Empedocles of Acragas



While Zeno and Melissus reinforced Parmenides' distinction
between what-is (i.e., what must be) and what appears, other
post-Parmenidean thinkers accepted Parmenides' arguments against
coming-to-be and passing-away (as characterizing what-is), and about
the stable nature of what is ultimately real, and argued that these
arguments did not rule out the possibility of metaphysically-based (or
rational) cosmology. Both Anaxagoras and Empedocles worked within the
Parmenidean pattern while developing distinct cosmological systems
that addressed their own particular concerns (especially in the case
of Empedocles, concerns about the proper way to live). 



Anaxagoras (writing in the mid-5th c.) claims, "The
Greeks [i.e., ordinary people] do not think correctly about
coming-to-be and passing-away; for no thing comes to be or passes
away, but is mixed together and dissociated from the things that are.
And thus they would be correct to call coming-to-be mixing-together
and passing-away dissociating" (DK59B17/LM25D15). What seem to
be generated objects (human beings, plants, animals, the moon, the
stars) are instead temporary mixtures of ingredients (such as earth,
air, fire, water, hair, flesh, blood, dense, dark, rare, bright, and
so on). Recent treatments of Anaxagoras (Marmodoro 2015, 2017) have
suggested that the ingredients are primarily powers that manifest
themselves in the mixtures
 produced.[7]
 The original state was universal mixture: "All things were
together, unlimited both in amount and in smallness, for the small,
too, was unlimited. And because all things were together, nothing was
evident" (DK59B1/LM25D9). This mixture is set into rotary motion
by the operation of Mind (*Nous* - DK59B12/LM25D27,
DKB13/LM25DD29b, DK59B14/LM25D28; see discussions in Laks 1993, Lesher
1995, Menn 1995, Curd 2007), a separate cosmic entity that does not
share in such mixture. As the rotation spreads out through the
unlimited mass of indistinguishably intermingled ingredients, the
rotation causes a winnowing or separating effect, and the cosmos as we
know it emerges from the mixture. Moreover, not only *were* all
things together, they are *even now* all together, in a
different way, despite the differentiations now achieved. Everything
is in everything (DK59B5, B6, B11/LM25D16, D25, D26), in some proportions, however small
or great - this is a move to prevent even the appearance of
coming-to-be from what-is-not. 



Anaxagoras marks an important theoretical step in attributing the
motion of his ingredients to an independent, intelligent force
(although both Plato and Aristotle were disappointed that his theory
was not properly--from their point of view--teleological; on
this see Sedley 2007, Curd 2018). The rotation begun by Mind is
causally responsible for the formation of the heavens and the
activities of the great masses of the earth and the water on the
earth, as well as all meteorological phenomena. Insofar as the causes
of the operations of the heavens and the phenomena apparent to us from
day to day are the same at both the macro- and micro-level (the
rotations that cause the apparent motions of the stars are the same as
those that govern the cycles of weather and life and death on earth),
we can infer the nature of what is real from what is apparent
(Anaxagoras' scientific views are treated in Graham 2006 and
2013). Although we do not perceive all things as being together, and
the move to the ultimate explanations is an inference, it is a
legitimate one ("owing to their [the senses'] feebleness,
we are not able to determine the truth" yet "appearances
are a sight of the unseen" DK59B21/LM25D5 and
DK59B21a/LM25D6).



A younger contemporary of Anaxagoras, Empedocles, who lived in Sicily,
also recognized the force of Parmenides' arguments against
coming-to-be and passing-away. (Empedocles also adopts
Parmenides' poetic meter in order to tell his story.) Empedocles
proposes a cosmos formed of the four roots (as he calls them), earth,
water, air, and fire along with the motive forces of Love and Strife.
It is often claimed that, for Empedocles, Love simply produces mixture
and Strife only causes separation. Empedocles' view is more
complicated, for both forces mix and separate. Love unites opposed
(unlike) things by pulling apart and then mixing these unlikes, while
Strife sets unlikes in opposition and segregates them, hence Strife
mixes like with like. Just as painters can produce fantastically
lifelike scenes just by mixing colors, so the operations of Love and
Strife, using just the four roots can produce "trees and men and
women, and beasts and birds and water-nourished fish, and long-lived
gods best in honors" (31B17). These are the things that
Empedocles calls "mortal," and he even provides recipes.
DK31B73/LM22D73 tells how Kypris (the goddess Aphrodite, i.e. love)
fashions shapes (or kinds): "she moistened earth in rain, and
gave it to quick fire to harden." DK31B96/LM44D192 gives a
recipe for bones; flesh and blood both have the same recipe (earth,
water, air, and fire in equal proportions), but differ in the
refinement of the mixture (DK31B98/LM44D58a and D190). 



Like the other Presocratics, Empedocles has a cosmological theory, in
his case, an unending cycle involving the competition between Love and
Strife. Love overcomes the separating influence of Strife, bringing
together unlikes and so preventing the clinging together of likes. The
triumph of Love results in the Sphere, which is a complete mixture
because the four unlike roots are as mixed (integrated) as possible.
Strife breaks up the sphere by beginning to attract like to like and
so pulling the mixture apart, until, when it triumphs, there is
complete segregation of the roots. Love resists the separation of
unlikes and the clinging together of likes, by trying to keep unlike
things mixed. The cosmos as we know it is a result of intermediate
phases between the two extremes of the triumph of one of the
 forces.[8]




Although Empedocles gives an account of the cosmos, cosmology is not
his sole interest. Both fragments and testimonia show his keen
attention to questions about perception and its role in knowledge, the
workings of the body, and psychology. Like the Pythagoreans,
Empedocles thought that how one lived was as important as one's
theoretical commitments (and that the two were intimately connected).
The ancient evidence seems to suggest that Empedocles was the author
of two works, commonly called in modern scholarship the
*Physics* and the *Purifications*, one cosmological and
the other ethico-religious. The relation between the two works has
been a matter of some controversy. In the 1990s important new evidence
from the Strasbourg Papyrus showed unequivocally that the cosmological
and ethico-religious aspects of Empedocles' thought are
inextricably intertwined (Martin and Primavesi 1999, Primavesi 2008,
Kingsley 1995), although commentators still disagree about whether
this new evidence supports the conclusion that there was a single poem
combining
 both.[9]
 The correct philosophical understanding of the physical world and the
correct way to live cannot be separated from one another in
Empedocles' thought (a similar attitude appears in Heraclitus);
one cannot fully understand the world without living
 correctly.[10]
 Like the Pythagorean, the Empedoclean way of life included dietary
restrictions and a story of transmigrating *daimons* who
seem to have some kind of personal identity. (Marmodoro 2016 is a
collection of recent work on Empedocles.)


## 8. Presocratic Atomism



The pluralism of Anaxagoras and Empedocles maintained the Eleatic
strictures on metaphysically acceptable basic entities (things that
are and must be just what they are) by adopting an irreducible
pluralism of stuffs meeting these standards that could pass on their
qualities to items constructed from them. Ancient atomism responded
more radically: what is real is an infinite number of solid,
uncuttable (*atomon*) units of matter. All atoms are made of
the same stuff (solid matter, in itself otherwise indeterminate),
differing from one another (according to Aristotle in *Metaphysics* 985b4-20=DK67A6/LM27D31 and R38) only in shape,
position, arrangement. Later sources say that atoms differ in weight;
some scholars have argued that, while this is certainly true for
post-Aristotelian atomism, it is less likely for Presocratic atomism.
Recent scholarship has questioned this view, and find no reason to
deny weight to Presocratic atomism (Augustin 2015). In addition to the
reality of atoms, the Presocratic atomists, Leucippus and Democritus
(Democritus was born in about 460 BCE in Abdera in Northern Greece,
shortly after Socrates was born in Athens), enthusiastically endorsed
the reality of the empty (or
 void).[11]
 The void is what separates atoms and allows for the differences noted
above (except weight, which could not be accounted for by void, since
void in an atom would make it divisible and, hence, not an atom)
(Sedley 1982; see also Sedley 2008). 



Like Anaxagoras, the atomists consider all phenomenal objects and
characteristics as emerging from the background mixture; in the case
of atomism, the mix of atoms and void (Wardy 1988). Everything is
constructed of atoms and void: the shapes of the atoms and their
arrangement with respect to each other (and the intervening void) give
physical objects their apparent characteristics. As Democritus says:
"By convention sweet and by convention bitter, by convention
hot, by convention cold, by convention color: in reality atoms and
void" (DK68B125/LM27D14, D13a = DK68B9/LM27D4, D14, D15, D23a,
R108). For example, Theophrastus says that the flavors differ
according to the shapes of the atoms that compose various objects;
thus "Democritus makes sweet that which is round and quite
large, astringent that which large, rough, polygonal and not
rounded" ( *Caus. Plant*. 6.1.6 = 68A129/LM27D60).
Simplicius reports that things composed of sharp and very fine atoms
in similar positions are hot and fiery; those composed of atoms with
the opposite character come to be cold and watery (*in Phys.*
36.3-6 = 67A14). Moreover, Theophrastus reports that the
atomists explain why iron is harder than lead but lighter; it is
harder because of the uneven arrangements of the atoms that make it
up, lighter because it contains more void than lead. Lead, on the
other hand, has less void than iron, but the even arrangement of the
atoms makes lead easier to cut or to bend (*de Sens.* 61-63 =
68A135/LM27D64, D65, D66, D67, D69, D134, D147, D157, D158, D159a).




Adopting a strong distinction between appearance and reality, and
denying the accuracy of appearances, as we see him do in the above
quotation, Democritus was seen by some ancient sources (especially
Sextus Empiricus) as a sort of skeptic, yet the evidence is unclear.
It is true that Democritus is quoted as saying, "In truth we
know nothing; for truth is in the depths" (DK68B117/LM27D24). So
for him, the truth is not given in the appearances. Yet, even Sextus
seems to agree that Democritus allows for knowledge:



> 
> But in the *Rules* [Democritus] says that there are two kinds
> of knowing, one through the senses and the other through the
> understanding. The one through the understanding he calls genuine,
> witnessing to its trustworthiness in deciding truth; the one through
> the senses he names bastard, denying it steadfastness in the
> discernment of what is true. He says in these words, "There are
> two forms of knowing, one genuine and the other bastard. To the
> bastard belong all these: sight, hearing, smell, taste, touch. The
> other, the genuine, has been separated from this"
> [DK68B11/LM27D6, D20, D21, R108]. Then preferring the genuine to the
> bastard, he continues, saying, "Whenever the bastard is no
> longer able to see more finely nor hear nor smell nor taste nor
> perceive by touch, but something finer..."
> 



Thus Sextus suggests that the evidence of the senses, when properly
interpreted by reason, can be taken as a guide to reality (the claim
that "appearances are a sight of the unseen" is attributed
to Democritus as well as to Anaxagoras). We just need to know how to
follow this guide, through proper reasoning, so as to reach the
truth--i.e., the theory of atoms and void (Lee 2005).



In addition to fragments advancing these metaphysical and physical
doctrines, there are a number of ethical fragments attributed to
Democritus (but the question of authenticity looms large here);
although a passage reported in John Stobaeus seems to link moderation
and cheerfulness with small measured movements in the soul and says
that excess and deficiencies give rise to large movements
(DK68B191/LMD226), it is unclear whether or how these claims are
related to the metaphysical aspects of atomism (Vlastos 1945 and 1946,
Kahn 1985b). Democritus was identified in antiquity with the idea of
"good cheer" (*euthumie*) as the proper
guiding objective in living one's life. In this, as in other
aspects of his philosophy, he may have had some influence on the
formation of Epicurus' philosophy a century later.


## 9. Diogenes of Apollonia and the Sophists



In the last part of the 5th century, Diogenes of Apollonia
(active after 440 BCE) revived and revised the Milesian system of
cosmology, claiming that "all the things that are are
alterations from the same thing and are the same thing"
(64B2/LM28D3); he identified this single basic substance with air,
like Anaximenes more than a century before (Graham 2006, Laks 2008,
2008a). Diogenes takes care to give arguments for the reality and
properties of his basic principle. In DK64B2/LM28D3 he says that only
things that are alike can affect one another. If there were a
plurality of basic substances, each differing in what Diogenes calls
their "own proper nature," there could be no interaction
between them. Yet the evidence of the senses is clear: things mix and
separate and interact with one another. Thus, all things must be forms
of some one single thing. Like Anaxagoras, Diogenes claims that the
cosmic system is ordered by intelligence, and he argues that that
"which possesses intelligence (*noesis*) is what
human beings call air" (DK64B5/LM28D10). Humans and animals live
by breathing air, and are governed by it --in them air is both
soul and intelligence, or mind (DK64B4/LM28D2). Moreover, Diogenes
argues, air governs and rules all things and is god (DK64B5/LM28D10).
Thus, like Anaxagoras, Diogenes has a theory grounded in intelligence,
although Diogenes is more fully committed to teleological
explanations, insofar as he states explicitly that intelligence
(*noesis*) orders things in a good way (DK64B3/LM28D56).
In presenting his arguments, Diogenes fulfills his own requirement for
a philosophical claim. In DK64B1/LM28D2 he says, "In my opinion,
anyone beginning a *logos* (account) ought to present a
starting principle (*arche*) that is indisputable and a
style that is simple and stately." He notes that his theory that
air is soul and intelligence "will have been made clearly
evident in this book" (DK64B4/LMD9). 



Theophrastus says that Diogenes was the last of the physical
philosophers, the *physiologoi*, or "inquirers into
nature," as Aristotle called them; Diogenes Laertius
(*Lives* II.16-17) gives that title to Archelaus, saying that
he was the teacher of Socrates (see Betegh 2013a). There was also
another group of thinkers active about this time: the Sophists. Many
of our views about this group have been shaped by Plato's
aggressively negative assessment of them: in his dialogues Plato
expressly contrasts the genuine philosopher, i.e., Socrates, with the
Sophists, especially in their role as teachers of young men growing
into their maturity (youths at the age when Socrates, too, engaged
with them in his discussions). Modern scholarship (Woodruff and
Gagarin 2008, Kerferd 1981, Guthrie 1969) has shown the diversity of
their views. They were not completely uninterested in the theoretical
problems that concerned others of the Presocratics. Gorgias of
Leontini questioned the possibility of the certainty that Parmenides
sought. In his *On Nature*, or *On what-is-not*, Gorgias
claims that nothing satisfies (or can satisfy) Parmenides'
requirements for what-is (Mansfeld 1985, Mourelatos 1987b, Palmer
1999, Caston 2002, Curd 2006). Protagoras, too, doubted the
possibility of the strong theoretical knowledge that the Presocratics
championed. The Sophists raised ethical and political questions: Does
law or convention ground what is right, or is it a matter of nature?
They traveled widely, sometimes serving as diplomats, and they were
both entertainers and teachers. They gave public displays of rhetoric
(this contrasts with Diogenes of Apollonia's comments about his
book, which seems to imply a more private
 enterprise)[12]
 and took on students, teaching both the art of rhetoric and the
skills necessary for succeeding in Greek political life. With the
Sophists, as with Socrates, interest in ethics and political thought
becomes a more prominent aspect of Greek philosophy.


## 10. The Presocratic Legacy



The range of Presocratic thought shows that the first philosophers
were not merely physicists (although they were certainly that). Their
interests extended to religious and ethical thought, the nature of
perception and understanding, mathematics, meteorology, the nature of
explanation, and the roles of matter, form, causal mechanisms, and
structure in the world. Almost all the Presocratics seemed to have
something to say about embryology, and fragments of Diogenes and
Empedocles show a keen interest in the structures of the body; the
overlap between ancient philosophy and ancient medicine is of growing
interest to scholars of early Greek thought (Longrigg 1963, van der
Eijk 2008). Recent discoveries, such as the Derveni Papyrus, show that
interest in and knowledge of the early philosophers was not
necessarily limited to a small audience of rationalistic
intellectuals. They passed on many of what later became the basic
concerns of philosophy to Plato and Aristotle, and ultimately to the
whole tradition of Western philosophical thought.