was an immensely influential ancient Greek philosopher, a student
of Socrates, writer of philosophical dialogues, and founder of the
Academy in Athens where Aristotle studied.
lectured extensively at the Academy, and wrote on many philosophical
issues, dealing especially in politics, ethics, metaphysics and
epistemology. The most important writings of Plato are his dialogues,
although a handful of epigrams also survived, and some letters
have come down to us under his name.
is believed that all of Plato's authentic dialogues survive. However,
some dialogues ascribed to Plato by the Greeks are now considered
by the consensus of scholars to be either suspect (e.g., First
Alcibiades, Clitophon) or probably spurious (such as Demodocus,
or the Second Alcibiades). The letters are all considered to probably
be spurious, with the possible exception of the Seventh Letter.
dialogues of Plato are lively, often humorous or ironic, full
of memorable characters and humble detail. It is generally agreed
that Plato is the most enjoyable of philosophers to read.
is often a character in the dialogues of Plato. How much of the
content and argument of any given dialogue is Socrates' point
of view, and how much of it is Plato's, is heavily disputed, since
Socrates himself did not write down his teachings; this ambiguity
is often referred to as the "Socratic problem". However,
Plato was doubtless strongly influenced by Socrates' teachings,
so many of the ideas presented, at least in his early works, were
likely borrowings or adaptations.
Plato was born in Athens or Aegina in May or December in 428 or
427 BC. He was raised in a moderately well-to-do aristocratic
family. His father was named Ariston, and his mother Perictione.
His family claimed descent from the ancient Athenian kings, and
he was related — though there is disagreement as to exactly
how — to the prominent politician Critias. According to
a late Hellenistic account by Diogenes Laertius, Plato's given
name was Aristocles, whereas his wrestling coach, Ariston of Argos,
dubbed him "Platon", meaning "broad" on account
of his robust figure.
mentions alternative accounts that Plato derived his name from
the breadth (platutês) of his eloquence, or else because
he was very wide (platus) across the forehead. According to Dicaearchus,
Plato wrestled at the Isthmian games. Such was his learning and
ability that the ancient Greeks declared him to be the son of
Apollo and told how, in his infancy, bees had settled on his lips,
as prophecy of the honeyed words which were to flow from them.
became a pupil of Socrates in his youth, and—at least according
to his own account—he attended his master's trial, though
not his execution. He was deeply affected by the city's treatment
of Socrates, and much of his early work records his memories of
his teacher. It is suggested that much of his ethical writing
is in pursuit of a society where similar injustices could not
occur. During the twelve years following the death of Socrates,
he traveled extensively in Italy, Sicily, Egypt, and Cyrene in
a quest for knowledge.
his return to Athens at the age of forty, Plato founded one of
the earliest known organized schools in Western civilization on
a plot of land in the Grove of Academe. The Academy was "a
large enclosure of ground which was once the property of a citizen
at Athens named Academus... some, however, say that it received
its name from an ancient hero" (Robinson, Arch. Graec. I
i 16), and it operated until 529, when it was closed by Justinian
I of Byzantium, who saw it as a threat to the propagation of Christianity.
Many intellectuals were schooled in the Academy, the most prominent
one being Aristotle.
was also deeply influenced by a number of prior philosophers,
including: the Pythagoreans, whose notions of numerical harmony
have clear echoes in Plato's notion of the Forms; Anaxagoras,
who taught Socrates and who held that the mind, or reason, pervades
everything; and Parmenides, who argued for the unity of all things
and may have influenced Plato's concept of the soul.
Unlike Socrates, Plato wrote down his philosophical views, leaving
behind a considerable number of manuscripts.
Plato's writings are debates concerning the best possible form
of government, featuring adherents of aristocracy, democracy,
monarchy, as well as other issues. A central theme is the conflict
between nature and convention, concerning the role of heredity
and the environment on human intelligence and personality long
before the modern "nature versus nurture" debate began
in the time of Thomas Hobbes and John Locke, with its modern continuation
in such controversial works as The Mismeasure of Man and The Bell
key distinction and theme in the Platonic corpus is the dichotomy
between knowledge and opinion, which foreshadow modern debates
between David Hume and Immanuel Kant, and has been taken up by
postmodernists and their opponents, more commonly as the distinction
between the objective and the subjective. Even the story of the
lost city or continent of Atlantis came to us as an illustrative
story told by Plato in his Timaeus and Critias.
also had a position on the art of writing as opposed to oral communication.
This is evidenced in his Phaedrus1 dialogue and his Seventh Epistle.2
He said that oral communication is superior to the written word,
especially in the accuracy of the oral word over the written word
and in his Seventh Epistle that nothing of importance should be
written down but transmitted orally.
Plato wrote mainly in the form known as dialogue. In the early
dialogues, several characters discuss a topic by asking questions
of one another. Socrates figures prominently, and a lively, more
disorganised form of elenchos/dialectic is present; these are
called the Socratic Dialogues.
nature of these dialogues changed a great deal over the course
of Plato's life. It is generally agreed that Plato's earlier works
are more closely based on Socrates' thought, whereas his later
writing increasingly breaks away from the views of his former
teacher. In the middle dialogues, Socrates becomes a mouthpiece
for Plato's own philosophy, and the question-and-answer style
is more pro forma: the main figure represents Plato and the minor
characters have little to say except "yes", "of
course" and "very true". The late dialogues read
more like treatises, and Socrates is often absent or quiet. It
is assumed that while some of the early dialogues could be based
on Socrates' actual conversations, the later dialogues were written
entirely by Plato. The question of which, if any, of the dialogues
are truly Socratic is known as the Socratic problem.
ostensible mise en scène of a dialogue distances both Plato
and a given reader from the philosophy being discussed; one can
choose between at least two options of perception: either to participate
in the dialogues, in the ideas being discussed, or choose to see
the content as expressive of the personalities contained within
dialogue format also allows Plato to put unpopular opinions in
the mouth of unsympathetic characters, such as Thrasymachus in
Platonism has traditionally been interpreted as a form of metaphysical
dualism, sometimes referred to as Platonic or Exaggerated Realism.
According to this reading, Plato's metaphysics divides the world
into two distinct aspects: the intelligible world of "forms",
and the perceptual world we see around us. The perceptual world
consists of imperfect copies of the intelligible forms or ideas.
These forms are unchangeable and perfect, and are only comprehensible
by the use of the intellect or understanding — i.e., a capacity
of the mind that does not include sense-perception or imagination.
division can also be found in Zoroastrian philosophy, in which
the dichotomy is referenced as the Minu (intelligence) and Giti
(perceptual) worlds. The Zoroastrian ideal city, Shahrivar, also
exhibits certain similarities with Plato's Republic. The existence
and direction of influence here is uncertain; while Zoroaster
lived well before Plato, few of the earliest writings of Zoroastrianism
the Republic Books VI and VII, Plato uses a number of metaphors
to explain his metaphysical views: the metaphor of the sun, the
well-known allegory of the cave, and most explicitly, the divided
together, these metaphors convey a complex, and, in places, difficult
theory: there is something called The Form of the Good (often
interpreted as Plato's god), which is the ultimate object of knowledge
and which, as it were, sheds light on all the other forms (i.e.,
universals: abstract kinds and attributes), and from which all
other forms "emanate". The Form of the Good does this
in somewhat the same way as the sun sheds light on, or makes visible
and "generates" things, in the perceptual world.
the perceptual world, the particular objects we see around us
bear only a dim resemblance to the more ultimately real forms
of Plato's intelligible world; it is as if we are seeing shadows
of cut-out shapes on the walls of a cave, which are mere representations
of the reality outside the cave, illuminated by the sun.
can imagine everything in the universe represented on a line of
increasing reality; it is divided once in the middle, and then
once again in each of the resulting parts. The first division
represents that between the intelligible and the perceptual worlds.
This is followed by a corresponding division in each of these
worlds: the segment representing the perceptual world is divided
into segments representing "real things" on the one
hand, and shadows, reflections, and representations on the other.
Similarly, the segment representing the intelligible world is
divided into segments representing first principles and most general
forms, on the one hand, and more derivative, "reflected"
forms, on the other.
metaphysics, and particularly its dualism between the intelligible
and the perceptual, would inspire later Neoplatonist thinkers,
such as Plotinus and Gnostics, and many other metaphysical realists.
Although Platonist philosophers like Plotinus rejected Gnosticism
(see Plotinus' Enneads). One reason being the Gnostic vilification
of nature and Plato's demiurge from Timaeus. Plato also influenced
Saint Justin Martyr. For more on Platonic realism in general,
see Platonic realism and the Forms.
this interpretation of Plato's writings (particularly the Republic)
has enjoyed immense popularity throughout the long history of
Western philosophy, it is also possible to interpret his suggestions
more conservatively, favoring a more epistemological than metaphysical
reading of such famous metaphors as the Cave and the Divided Line.
There are obvious parallels between the Cave allegory and the
life of Plato's teacher Socrates (who was killed in his attempt
to "open the eyes" of the Athenians). This example reveals
the dramatic complexity that often lies under the surface of Plato's
writing (remember that in the Republic, it is Socrates who relates
Plato also had some influential opinions on the nature of knowledge
and learning which he propounded in the Meno, which began with
the question of whether virtue can be taught, and proceeded to
expound the concepts of recollection, learning as the discovery
of pre-existing knowledge, and right opinion, opinions which are
correct but have no clear justification.
stated that knowledge is essentially justified true belief, an
influential belief which informed future developments in epistemology.
In the Theaetetus, Plato argued that belief is to be distinguished
from knowledge on account of justification. Many years later,
Edmund Gettier famously demonstrated the problems of the justified
true belief account of knowledge.
Plato's philosophical views had many societal implications, especially
on the idea of an ideal state or government. There is some discrepancy
between his early and later views. Some of the most famous doctrines
are contained in the Republic during his middle period.
asserts that societies have a tripartite class structure corresponding
to the appetite/spirit/reason structure of the individual soul.
Productive (Workers) — the labourers, carpenters, plumbers,
masons, merchants, farmers, ranchers, etc. These correspond to
the "appetite" part of the soul.
2. Protective (Warriors) — those who are adventurous, strong,
brave, in love with danger; in the armed forces. These correspond
to the "spirit" part of the soul.
3. Governing (Rulers) — those who are intelligent, rational,
self-controlled, in love with wisdom, well suited to make decisions
for the community. These correspond to the "reason"
part of the soul and are very few.
to this model, the principles of Athenian democracy (as it existed
in his day) are rejected as only a few are fit to rule. Instead
of rhetoric and persuasion, Plato says reason and wisdom should
govern. This does not equate to tyranny, despotism, or oligarchy,
however. As Plato puts it:
philosophers rule as kings or those who are now called kings and
leading men genuinely and adequately philosophise, that is, until
political power and philosophy entirely coincide, while the many
natures who at present pursue either one exclusively are forcibly
prevented from doing so, cities will have no rest from evils,...
nor, I think, will the human race."
describes these "philosopher kings" as "those who
love the sight of truth" (Republic 475c) and supports the
idea with the analogy of a captain and his ship or a doctor and
his medicine. Sailing and health are not things that everyone
is qualified to practice by nature. A large part of the Republic
then addresses how the educational system should be set up to
produce these philosopher kings.
it must be taken into account that the ideal city outlined in
the Republic is qualified by Socrates as the ideal luxurious city,
examined to determine how it is that injustice and justice grow
in a city (Republic 372e). According to Socrates, the "true"
and "healthy" city is instead the one first outlined
in book II of the Republic, 369c-372d, containing farmers, craftsmen,
merchants, and wage-earners, but lacking the guardian class of
philosopher-kings as well as delicacies such as "perfumed
oils, incense, prostitutes, and pastries", in addition to
paintings, gold, ivory, couches, a multitude of occupations such
as poets and hunters, and war.
Plato's thought is often compared with that of his most famous
student, Aristotle, whose reputation during the Western Middle
Ages so completely eclipsed that of Plato that the Scholastic
philosophers referred to Aristotle as "the Philosopher".
However, in the Byzantine Empire, the study of Plato continued.
Medieval scholastic philosophers did not have access to the works
of Plato—nor the knowledge of Greek needed to read them.
Plato's original writings were essentially lost to Western civilization
until they were brought from Constantinople in the century before
its fall, by George Gemistos Plethon. Medieval scholars knew of
Plato only through translations into Latin from the translations
into Arabic by Persian and Arab scholars. These scholars not only
translated the texts of the ancients, but expanded them by writing
extensive commentaries and interpretations on Plato's and Aristotle's
works (see Al-Farabi, Avicenna, Averroes).
in the Renaissance, with the general resurgence of interest in
classical civilization, did knowledge of Plato's philosophy become
widespread again in the West. Many of the greatest early modern
scientists and artists who broke with Scholasticism and fostered
the flowering of the Renaissance, with the support of the Plato-inspired
Lorenzo de Medici, saw Plato's philosophy as the basis for progress
in the arts and sciences. By the 19th century, Plato's reputation
was restored, and at least on par with Aristotle's.
Western philosophers have continued to draw upon Plato's work
since that time. Plato's influence has been especially strong
in mathematics and the sciences. It inspired the greatest advances
in logic since Aristotle, due to Gottlob Frege and his followers
Kurt Gödel, Alonzo Church, and Alfred Tarski, the last of
whom summarised his approach by reversing Aristotle's famous declaration
of sedition from the Academy: Inimicus Plato, sed magis inimica
falsitas ("Plato is an enemy, but falsehood is yet a greater
Einstein drew on Plato's understanding of an immutable reality
that underlies the flux of appearances for his objections to the
probabilistic picture of the physical universe propounded by Niels
Bohr in his interpretation of quantum mechanics. Conversely, thinkers
that diverged from ontological models and moral ideals in their
own philosophy, have tended to disparage Platonism from more or
less informed perspectives. Thus Friedrich Nietzsche attacked
Plato's moral and political theories, Martin Heidegger argued
against Plato's alleged obfuscation of Being, and Karl Popper
argued in The Open Society and Its Enemies (1945) that Plato's
proposal for a government system in the Republic was prototypically
Plato's writings (most of them dialogues) have been published
in several fashions; this has led to several conventions regarding
the naming and referencing of Plato's texts.
One tradition regarding the arrangement of Plato's texts is according
to tetralogies. This scheme is ascribed by Diogenes Laertius to
an ancient scholar and court astrologer to Tiberius named Thrasyllus.
the list below, works by Plato are marked (1) if there is no consensus
among scholars as to whether Plato is the author, and (2) if scholars
generally agree that Plato is not the author of the work. Unmarked
works are assumed to have been written by Plato.
I. Euthyphro, (The) Apology (of Socrates), Crito, Phaedo
II. Cratylus, Theaetetus, Sophist, Statesman
III. Parmenides, Philebus, (The) Symposium, Phaedrus
IV. First Alcibiades (1), Second Alcibiades (2), Hipparchus (2),
(The) (Rival) Lovers (2)
V. Theages (2), Charmides, Laches, Lysis
VI. Euthydemus, Protagoras, Gorgias, Meno
VII. (Greater) Hippias (major) (1), (Lesser) Hippias (minor),
VIII. Clitophon (1), (The) Republic, Timaeus, Critias
IX. Minos (2), (The) Laws, Epinomis (2), Letters (1)
not in tetralogies
The remaining works were transmitted under Plato's name, most
of them already considered spurious in antiquity:
(2), Definitions (2), Demodocus (2), Epigrams, Eryxias (2), Halcyon
(2), On Justice (2), On Virtue (2), Sisyphus (2)
The usual system for making unique references to sections of the
text by Plato derives from a 16th century edition of Plato's works
by Henricus Stephanus. An overview of Plato's writings according
to this system can be found in the Stephanus pagination article.
The exact order in which Plato's dialogues were written is not
known, nor is the extent to which some might have been later revised
and rewritten. However, there is enough information internal to
the dialogues to form a rough chronology. The dialogues are normally
grouped into three fairly distinct periods, with a few of them
considered transitional works, and some just difficult to place.
of the positions in this ordering are still highly disputed.
Socrates figures in all of these, and they are considered the
most faithful representations of the historical Socrates; hence
they are also called the Socratic dialogues. Most of them consist
of Socrates discussing a subject, often an ethical one (friendship,
piety) with a friend or with someone presumed to be an expert
on it. Through a series of questions he will show that they don't
apparently understand it at all. This period also includes several
pieces surrounding the trial and execution of Socrates.
8. Lesser Hippias
following are variously considered transitional or middle period
Late in the early dialogues Plato's Socrates actually begins supplying
answers to some of the questions he asks, or putting forth positive
doctrines. This is generally seen as the first appearance of Plato's
own views. The first of these, that goodness is wisdom and that
no one does evil willingly, was perhaps Socrates' own view. What
becomes most prominent in the middle dialogues is the idea that
knowledge comes of grasping unchanging forms or essences, paired
with the attempts to investigate such essences. The immortality
of the soul, and specific doctrines about justice, truth, and
beauty, begin appearing here. The Symposium and the Republic are
considered the centrepieces of Plato's middle period.
The Parmenides presents a series of criticisms of the theory of
Forms which are widely taken to indicate Plato's abandonment of
the doctrine. Some recent publications (e.g., Meinwald (1991))
have challenged this characterisation. In most of the remaining
dialogues the theory is either absent or at least appears under
a different guise in discussions about kinds or classes of things
(the Timaeus may be an important, and hence controversially placed,
is either absent or a minor figure in the discussion. An apparently
new method for doing dialectic known as "collection and division"
is also featured, most notably in the Sophist and Politicus, explicitly
for the first time in the Phaedrus, and possibly in the Philebus.
There is a question about the efficacy of the method for arriving
at the answers to philosophical questions; it appears to rely
for its results on little more than what its practitioners already
believe or find intuitively plausible.
that case it is not clear how it can bring about any progress
on matters under discussion, and it has been suggested that the
method is a sign of Plato's failing philosophical powers in his
later life. It is far more likely, though, that scholars have
simply yet to arrive at an adequate characterisation of the method.
basic description of collection and division would go as follows:
interlocutors attempt to discern the similarities and differences
among things in order to get clear idea about what they in fact
are. One understanding, suggested in some passages of the Sophist,
is that this is what philosophy is always in the business of doing,
and is doing even in the early dialogues.
late dialogues are also an important place to look for Plato's
mature thought on most of the issues dealt with in the earlier
dialogues. There is much work still to be done by scholars on
the working out of what these views are. The later works are agreed
to be difficult and challenging pieces of philosophy. On the whole
they are more sober and logical than earlier works, but may hold
out the promise of steps towards a solution to problems which
were systematically laid out in prior works.