Aristotle
Greek philosopher
born 384 bc, Stagira, Chalcidice, Greece
died 322, Chalcis, Euboea
Overview
Greek philosopher and scientist whose thought determined the
course of Western intellectual history for two millenia.
He was the son of the court physician to Amyntas III,
grandfather of Alexander the Great. In 367 he became a
student at the Academy of Plato in Athens; he remained there
for 20 years. After Plato’s death in 348/347, he returned to
Macedonia, where he became tutor to the young Alexander. In
335 he founded his own school in Athens, the Lyceum. His
intellectual range was vast, covering most of the sciences
and many of the arts. He worked in physics, chemistry,
biology, zoology, and botany; in psychology, political
theory, and ethics; in logic and metaphysics; and in
history, literary theory, and rhetoric. He invented the
study of formal logic, devising for it a finished system,
known as syllogistic, that was considered the sum of the
discipline until the 19th century; his work in zoology, both
observational and theoretical, also was not surpassed until
the 19th century. His ethical and political theory,
especially his conception of the ethical virtues and of
human flourishing (“happiness”), continue to exert great
influence in philosophical debate. He wrote prolifically;
his major surviving works include the Organon, De Anima (“On
the Soul”), Physics, Metaphysics, Nicomachean Ethics,
Eudemian Ethics, Magna Moralia, Politics, Rhetoric, and
Poetics, as well as other works on natural history and
science. See also teleology.
Main
ancient Greek philosopher and scientist, one of the greatest
intellectual figures of Western history. He was the author
of a philosophical and scientific system that became the
framework and vehicle for both Christian Scholasticism and
medieval Islamic philosophy. Even after the intellectual
revolutions of the Renaissance, the Reformation, and the
Enlightenment, Aristotelian concepts remained embedded in
Western thinking.
Aristotle’s intellectual range was vast, covering most of
the sciences and many of the arts, including biology,
botany, chemistry, ethics, history, logic, metaphysics,
rhetoric, philosophy of mind, philosophy of science,
physics, poetics, political theory, psychology, and zoology.
He was the founder of formal logic, devising for it a
finished system that for centuries was regarded as the sum
of the discipline; and he pioneered the study of zoology,
both observational and theoretical, in which some of his
work remained unsurpassed until the 19th century. But he is,
of course, most outstanding as a philosopher. His writings
in ethics and political theory as well as in metaphysics and
the philosophy of science continue to be studied, and his
work remains a powerful current in contemporary
philosophical debate.
This article deals with Aristotle’s life and thought. For
the later development of Aristotelian philosophy, see
Aristotelianism. For treatment of Aristotelianism in the
full context of Western philosophy, see philosophy, Western.
Life » The Academy
Aristotle was born on the Chalcidic peninsula of Macedonia,
in northern Greece. His father, Nicomachus, was the
physician of Amyntas III (reigned c. 393–c. 370 bc), king of
Macedonia and grandfather of Alexander the Great (reigned
336–323 bc). After his father’s death in 367, Aristotle
migrated to Athens, where he joined the Academy of Plato (c.
428–c. 348 bc). He remained there for 20 years as Plato’s
pupil and colleague.
Many of Plato’s later dialogues date from these decades,
and they may reflect Aristotle’s contributions to
philosophical debate at the Academy. Some of Aristotle’s
writings also belong to this period, though mostly they
survive only in fragments. Like his master, Aristotle wrote
initially in dialogue form, and his early ideas show a
strong Platonic influence. His dialogue Eudemus, for
example, reflects the Platonic view of the soul as
imprisoned in the body and as capable of a happier life only
when the body has been left behind. According to Aristotle,
the dead are more blessed and happier than the living, and
to die is to return to one’s real home.
Another youthful work, the Protrepticus (“Exhortation”),
has been reconstructed by modern scholars from quotations in
various works from late antiquity. Everyone must do
philosophy, Aristotle claims, because even arguing against
the practice of philosophy is itself a form of
philosophizing. The best form of philosophy is the
contemplation of the universe of nature; it is for this
purpose that God made human beings and gave them a godlike
intellect. All else—strength, beauty, power, and honour—is
worthless.
It is possible that two of Aristotle’s surviving works on
logic and disputation, the Topics and the Sophistical
Refutations, belong to this early period. The former
demonstrates how to construct arguments for a position one
has already decided to adopt; the latter shows how to detect
weaknesses in the arguments of others. Although neither work
amounts to a systematic treatise on formal logic, Aristotle
can justly say, at the end of the Sophistical Refutations,
that he has invented the discipline of logic—nothing at all
existed when he started.
During Aristotle’s residence at the Academy, King Philip
II of Macedonia (reigned 359–336 bc) waged war on a number
of Greek city-states. The Athenians defended their
independence only half-heartedly, and, after a series of
humiliating concessions, they allowed Philip to become, by
338, master of the Greek world. It cannot have been an easy
time to be a Macedonian resident in Athens.
Within the Academy, however, relations seem to have
remained cordial. Aristotle always acknowledged a great debt
to Plato; he took a large part of his philosophical agenda
from Plato, and his teaching is more often a modification
than a repudiation of Plato’s doctrines. Already, however,
Aristotle was beginning to distance himself from Plato’s
theory of Forms, or Ideas (eidos; see form). (The word Form,
when used to refer to Forms as Plato conceived them, is
often capitalized in the scholarly literature; when used to
refer to forms as Aristotle conceived them, it is
conventionally lowercased.) Plato had held that, in addition
to particular things, there exists a suprasensible realm of
Forms, which are immutable and everlasting. This realm, he
maintained, makes particular things intelligible by
accounting for their common natures: a thing is a horse, for
example, by virtue of the fact that it shares in, or
imitates, the Form of “Horse.” In a lost work, On Ideas,
Aristotle maintains that the arguments of Plato’s central
dialogues establish only that there are, in addition to
particulars, certain common objects of the sciences. In his
surviving works as well, Aristotle often takes issue with
the theory of Forms, sometimes politely and sometimes
contemptuously. In his Metaphysics he argues that the theory
fails to solve the problems it was meant to address. It does
not confer intelligibility on particulars, because immutable
and everlasting Forms cannot explain how particulars come
into existence and undergo change. All the theory does,
according to Aristotle, is introduce new entities equal in
number to the entities to be explained—as if one could solve
a problem by doubling it.(See below Doctrines: Physics and
metaphysics: Form.)
Life » Travels
When Plato died about 348, his nephew Speusippus became head
of the Academy, and Aristotle left Athens. He migrated to
Assus, a city on the northwestern coast of Anatolia (in
present-day Turkey), where Hermias, a graduate of the
Academy, was ruler. Aristotle became a close friend of
Hermias and eventually married his ward Pythias. Aristotle
helped Hermias to negotiate an alliance with Macedonia,
which angered the Persian king, who had Hermias
treacherously arrested and put to death. Aristotle saluted
Hermias’s memory in Ode to Virtue, his only surviving poem.
While in Assus and during the subsequent few years when
he lived in the city of Mytilene on the island of Lesbos,
Aristotle carried out extensive scientific research,
particularly in zoology and marine biology. This work was
summarized in a book later known, misleadingly, as The
History of Animals, to which Aristotle added two short
treatises, On the Parts of Animals and On the Generation of
Animals. Although Aristotle did not claim to have founded
the science of zoology, his detailed observations of a wide
variety of organisms were quite without precedent. He—or one
of his research assistants—must have been gifted with
remarkably acute eyesight, since some of the features of
insects that he accurately reports were not again observed
until the invention of the microscope in the 17th century.
The scope of Aristotle’s scientific research is
astonishing. Much of it is concerned with the classification
of animals into genus and species; more than 500 species
figure in his treatises, many of them described in detail.
The myriad items of information about the anatomy, diet,
habitat, modes of copulation, and reproductive systems of
mammals, reptiles, fish, and insects are a melange of minute
investigation and vestiges of superstition. In some cases
his unlikely stories about rare species of fish were proved
accurate many centuries later. In other places he states
clearly and fairly a biological problem that took millennia
to solve, such as the nature of embryonic development.
Despite an admixture of the fabulous, Aristotle’s
biological works must be regarded as a stupendous
achievement. His inquiries were conducted in a genuinely
scientific spirit, and he was always ready to confess
ignorance where evidence was insufficient. Whenever there is
a conflict between theory and observation, one must trust
observation, he insisted, and theories are to be trusted
only if their results conform with the observed phenomena.
About eight years after the death of Hermias, in 343 or
342, Aristotle was summoned by Philip II to the Macedonian
capital at Pella to act as tutor to Philip’s 13-year-old
son, the future Alexander the Great. Little is known of the
content of Aristotle’s instruction; although the Rhetoric to
Alexander was included in the Aristotelian corpus for
centuries, it is now commonly regarded as a forgery. By 326
Alexander had made himself master of an empire that
stretched from the Danube to the Indus and included Libya
and Egypt. Ancient sources report that during his campaigns
Alexander arranged for biological specimens to be sent to
his tutor from all parts of Greece and Asia Minor.
Life » The Lyceum
While Alexander was conquering Asia, Aristotle, now 50 years
old, was in Athens. Just outside the city boundary, he
established his own school in a gymnasium known as the
Lyceum. He built a substantial library and gathered around
him a group of brilliant research students, called
“peripatetics” from the name of the cloister (peripatos) in
which they walked and held their discussions. The Lyceum was
not a private club like the Academy; many of the lectures
there were open to the general public and given free of
charge.
Most of Aristotle’s surviving works, with the exception
of the zoological treatises, probably belong to this second
Athenian sojourn. There is no certainty about their
chronological order, and indeed it is probable that the main
treatises—on physics, metaphysics, psychology, ethics, and
politics—were constantly rewritten and updated. Every
proposition of Aristotle is fertile of ideas and full of
energy, though his prose is commonly neither lucid nor
elegant.
Aristotle’s works, though not as polished as Plato’s, are
systematic in a way that Plato’s never were. Plato’s
dialogues shift constantly from one topic to another, always
(from a modern perspective) crossing the boundaries between
different philosophical or scientific disciplines. Indeed,
there was no such thing as an intellectual discipline until
Aristotle invented the notion during his Lyceum period.
Aristotle divided the sciences into three kinds:
productive, practical, and theoretical. The productive
sciences, naturally enough, are those that have a product.
They include not only engineering and architecture, which
have products like bridges and houses, but also disciplines
such as strategy and rhetoric, where the product is
something less concrete, such as victory on the battlefield
or in the courts. The practical sciences, most notably
ethics and politics, are those that guide behaviour. The
theoretical sciences are those that have no product and no
practical goal but in which information and understanding
are sought for their own sake.
During Aristotle’s years at the Lyceum, his relationship
with his former pupil Alexander apparently cooled. Alexander
became more and more megalomaniac, finally proclaiming
himself divine and demanding that Greeks prostrate
themselves before him in adoration. Opposition to this
demand was led by Aristotle’s nephew Callisthenes (c.
360–327 bc), who had been appointed historian of Alexander’s
Asiatic expedition on Aristotle’s recommendation. For his
heroism Callisthenes was falsely implicated in a plot and
executed.
When Alexander died in 323, democratic Athens became
uncomfortable for Macedonians, even those who were
anti-imperialist. Saying that he did not wish the city that
had executed Socrates “to sin twice against philosophy,”
Aristotle fled to Chalcis, where he died the following year.
His will, which survives, makes thoughtful provision for a
large number of friends and dependents. To Theophrastus (c.
372–c. 287 bc), his successor as head of the Lyceum, he left
his library, including his own writings, which were vast.
Aristotle’s surviving works amount to about one million
words, though they probably represent only about one-fifth
of his total output.
Writings
Aristotle’s writings fall into two groups: those that were
published by him but are now almost entirely lost, and those
that were not intended for publication but were collected
and preserved by others. The first group consists mainly of
popular works; the second group comprises treatises that
Aristotle used in his teaching.
Writings » Lost works
The lost works include poetry, letters, and essays as well
as dialogues in the Platonic manner. To judge by surviving
fragments, their content often differed widely from the
doctrines of the surviving treatises. The commentator
Alexander of Aphrodisias (born c. 200) suggested that
Aristotle’s works may express two truths: an “exoteric”
truth for public consumption and an “esoteric” truth
reserved for students in the Lyceum. Most contemporary
scholars, however, believe that the popular writings reflect
not Aristotle’s public views but rather an early stage of
his intellectual development.
Writings » Extant works
The works that have been preserved derive from manuscripts
left by Aristotle on his death. According to ancient
tradition—passed on by Plutarch (ad 46–c. 119) and Strabo
(c. 64 bc–ad 23?)—the writings of Aristotle and Theophrastus
were bequeathed to Neleus of Scepsis, whose heirs hid them
in a cellar to prevent their being confiscated for the
library of the kings of Pergamum (in present-day Turkey).
Later, according to this tradition, the books were purchased
by a collector and taken to Athens, where they were
commandeered by the Roman commander Sulla when he conquered
the city in 86 bc. Taken to Rome, they were edited and
published there about 60 bc by Andronicus of Rhodes, the
last head of the Lyceum. Although many elements of this
story are implausible, it is still widely accepted that
Andronicus edited Aristotle’s texts and published them with
the titles and in the form and order that are familiar
today.
Doctrines » Logic » Syllogistic
Aristotle’s claim to be the founder of logic rests primarily
on the Categories, the De interpretatione, and the Prior
Analytics, which deal respectively with words, propositions,
and syllogisms. These works, along with the Topics, the
Sophistical Refutations, and a treatise on scientific
method, the Posterior Analytics, were grouped together in a
collection known as the Organon, or “tool” of thought.
The Prior Analytics is devoted to the theory of the
syllogism, a central method of inference that can be
illustrated by familiar examples such as the following:
Every Greek is human. Every human is mortal. Therefore,
every Greek is mortal.
Aristotle discusses the various forms that syllogisms can
take and identifies which forms constitute reliable
inferences. The example above contains three propositions in
the indicative mood, which Aristotle calls “propositions.”
(Roughly speaking, a proposition is a proposition considered
solely with respect to its logical features.) The third
proposition, the one beginning with “therefore,” Aristotle
calls the conclusion of the syllogism. The other two
propositions may be called premises, though Aristotle does
not consistently use any particular technical term to
distinguish them.
The propositions in the example above begin with the word
every; Aristotle calls such propositions “universal.” (In
English, universal propositions can be expressed by using
all rather than every; thus, Every Greek is human is
equivalent to All Greeks are human.) Universal propositions
may be affirmative, as in this example, or negative, as in
No Greek is a horse. Universal propositions differ from
“particular” propositions, such as Some Greek is bearded (a
particular affirmative) and Some Greek is not bearded (a
particular negative). In the Middle Ages it became customary
to call the difference between universal and particular
propositions a difference of “quantity” and the difference
between affirmative and negative propositions a difference
of “quality.”
In propositions of all these kinds, Aristotle says,
something is predicated of something else. The items that
enter into predications Aristotle calls “terms.” It is a
feature of terms, as conceived by Aristotle, that they can
figure either as predicates or as subjects of predication.
This means that they can play three distinct roles in a
syllogism. The term that is the predicate of the conclusion
is the “major” term; the term of which the major term is
predicated in the conclusion is the “minor” term; and the
term that appears in each of the premises is the “middle”
term.
In addition to inventing this technical vocabulary,
Aristotle introduced the practice of using schematic letters
to identify particular patterns of argument, a device that
is essential for the systematic study of inference and that
is ubiquitous in modern mathematical logic. Thus, the
pattern of argument exhibited in the example above can be
represented in the schematic proposition:
If A belongs to every B, and B belongs to every C, A
belongs to every C.
Because propositions may differ in quantity and quality,
and because the middle term may occupy several different
places in the premises, many different patterns of
syllogistic inference are possible. Additional examples are
the following:
Every Greek is human. No human is immortal. Therefore, no
Greek is immortal.
Some animal is a dog. Some dog is white. Therefore, every
animal is white.
From late antiquity, triads of these different kinds were
called “moods” of the syllogism. The two moods illustrated
above exhibit an important difference: the first is a valid
argument, and the second is an invalid argument, having true
premises and a false conclusion. An argument is valid only
if its form is such that it will never lead from true
premises to a false conclusion. Aristotle sought to
determine which forms result in valid inferences. He set out
a number of rules giving necessary conditions for the
validity of a syllogism, such as the following:
At least one premise must be universal.
At least one premise must be affirmative.
If either premise is negative, the conclusion must be
negative.
Aristotle’s syllogistic is a remarkable achievement: it
is a systematic formulation of an important part of logic.
From roughly the Renaissance until the early 19th century,
it was widely believed that syllogistic was the whole of
logic. But in fact it is only a fragment. It does not deal,
for example, with inferences that depend on words such as
and, or, and if…then, which, instead of attaching to nouns,
link whole propositions together.
Doctrines » Logic » Propositions and categories
Aristotle’s writings show that even he realized that there
is more to logic than syllogistic. The De interpretatione,
like the Prior Analytics, deals mainly with general
propositions beginning with Every, No, or Some. But its main
concern is not to link these propositions to each other in
syllogisms but to explore the relations of compatibility and
incompatibility between them. Every swan is white and No
swan is white clearly cannot both be true; Aristotle calls
such pairs of propositions “contraries.” They can, however,
both be false, if—as is the case—some swans are white and
some are not. Every swan is white and Some swan is not
white, like the former pair, cannot both be true, but—on the
assumption that there are such things as swans—they cannot
both be false either. If one of them is true, the other is
false; and if one of them is false, the other is true.
Aristotle calls such pairs of propositions
“contradictories.”
The propositions that enter into syllogisms are all
general propositions, whether universal or particular; that
is to say, none of them is a proposition about an
individual, containing a proper name, such as the
proposition Socrates is wise. To find a systematic treatment
of singular propositions, one must turn to the Categories.
This treatise begins by dividing the “things that are said”
(the expressions of speech) into those that are simple and
those that are complex. Examples of complex sayings are A
man runs, A woman speaks, and An ox drinks; simple sayings
are the particular words that enter into such complexes:
man, runs, woman, speaks, and so on. Only complex sayings
can be statements, true or false; simple sayings are neither
true nor false. The Categories identifies 10 different ways
in which simple expressions may signify; these are the
categories that give the treatise its name. To introduce the
categories, Aristotle employs a heterogeneous set of
expressions, including nouns (e.g., substance), verbs (e.g.,
wearing), and interrogatives (e.g., where? or how big?). By
the Middle Ages it had become customary to refer to each
category by a more or less abstract noun: substance,
quantity, quality, relation, place, time, posture, vesture,
activity, and passivity.
The categories are intended as a classification of both
the kinds of expression that may function as a predicate in
a proposition and of the kinds of extralinguistic entity
such expressions may signify. One might say of Socrates, for
example, that he was human (substance), that he was five
feet tall (quantity), that he was wise (quality), that he
was older than Plato (relation), and that he lived in Athens
(place) in the 5th century bc (time). On a particular
occasion, his friends might have said of him that he was
sitting (posture), wearing a cloak (vesture), cutting a
piece of cloth (activity), or being warmed by the sun
(passivity).
If one follows Aristotle’s lead, one will easily be able
to classify the predicates in propositions such as Socrates
is potbellied and Socrates is wiser than Meletus. But what
about the term Socrates in propositions such as Socrates is
human? What category does it belong to? Aristotle answers
the question by making a distinction between “first
substance” and “second substance.” In Socrates is human,
Socrates refers to a first substance—an individual—and human
to a second substance—a species or kind. Thus, the
proposition predicates the species human of an individual,
Socrates.(See below Physics and metaphysics: Form.)
Aristotle’s logical writings contain two different
conceptions of the structure of a proposition and the nature
of its parts. One conception can trace its ancestry to
Plato’s dialogue the Sophist. In that work Plato introduces
a distinction between nouns and verbs, a verb being the sign
of an action and a noun being the sign of an agent of an
action. A proposition, he claims, must consist of at least
one noun and at least one verb; two nouns in succession or
two verbs in succession—as in lion stag and walks runs—will
never make a proposition. The simplest kind of proposition
is something like A man learns or Theaetetus flies, and only
something with this kind of structure can be true or false.
It is this conception of a proposition as constructed from
two quite heterogeneous elements that is to the fore in the
Categories and the De interpretatione, and it is also
paramount in modern logic.
In the syllogistic of the Prior Analytics, in contrast,
the proposition is conceived in quite a different way. The
basic elements out of which it is constructed are terms,
which are not heterogeneous like nouns and verbs but can
occur indifferently, without change of meaning, as either
subjects or predicates. One flaw in the doctrine of terms is
that it fosters confusion between signs and what they
signify. In the proposition Every human is mortal, for
example, is mortal predicated of humans or of human? It is
important to distinguish between use and mention—between the
use of a word to talk about what it signifies and the
mention of a word to talk about the word itself. This
distinction was not always easy to make in ancient Greek,
because the language lacked quotation marks. There is no
doubt that Aristotle sometimes fell into confusion between
use and mention; the wonder is that, given his dysfunctional
doctrine of terms, he did not do so more often.
Doctrines » Physics and metaphysics
Aristotle divided the theoretical sciences into three
groups: physics, mathematics, and theology. Physics as he
understood it was equivalent to what would now be called
“natural philosophy,” or the study of nature (physis; see
also nature, philosophy of); in this sense it encompasses
not only the modern field of physics but also biology,
chemistry, geology, psychology, and even meteorology.
Metaphysics, however, is notably absent from Aristotle’s
classification; indeed, he never uses the word, which first
appears in the posthumous catalog of his writings as a name
for the works listed after the Physics. He does, however,
recognize the branch of philosophy now called metaphysics:
he calls it “first philosophy” and defines it as the
discipline that studies “being as being.”
Aristotle’s contributions to the physical sciences are
less impressive than his researches in the life sciences. In
works such as On Generation and Corruption and On the
Heavens, he presented a world-picture that included many
features inherited from his pre-Socratic predecessors. From
Empedocles (c. 490–430 bc) he adopted the view that the
universe is ultimately composed of different combinations of
the four fundamental elements of earth, water, air, and
fire. Each element is characterized by the possession of a
unique pair of the four elementary qualities of heat, cold,
wetness, and dryness: earth is cold and dry, water is cold
and wet, air is hot and wet, and fire is hot and dry. Each
element has a natural place in an ordered cosmos, and each
has an innate tendency to move toward this natural place.
Thus, earthy solids naturally fall, while fire, unless
prevented, rises ever higher. Other motions of the elements
are possible but are “violent.” (A relic of Aristotle’s
distinction is preserved in the modern-day contrast between
natural and violent death.)
Aristotle’s vision of the cosmos also owes much to
Plato’s dialogue Timaeus. As in that work, the Earth is at
the centre of the universe, and around it the Moon, the Sun,
and the other planets revolve in a succession of concentric
crystalline spheres. The heavenly bodies are not compounds
of the four terrestrial elements but are made up of a
superior fifth element, or “quintessence.” In addition, the
heavenly bodies have souls, or supernatural intellects,
which guide them in their travels through the cosmos.
Even the best of Aristotle’s scientific work has now only
a historical interest. The abiding value of treatises such
as the Physics lies not in their particular scientific
assertions but in their philosophical analyses of some of
the concepts that pervade the physics of different
eras—concepts such as place, time, causation, and
determinism.
Doctrines » Physics and metaphysics » Place
Every body appears to be in some place, and every body (at
least in principle) can move from one place to another. The
same place can be occupied at different times by different
bodies, as a flask can contain first wine and then air. So a
place cannot be identical to the body that occupies it.
What, then, is place? According to Aristotle, the place of a
thing is the first motionless boundary of whatever body is
containing it. Thus, the place of a pint of wine is the
inner surface of the flask containing it—provided the flask
is stationary. But suppose the flask is in motion, perhaps
on a punt floating down a river. Then the wine will be
moving too, from place to place, and its place must be given
by specifying its position relative to the motionless river
banks.
As is clear from this example, for Aristotle a thing is
not only in the place defined by its immediate container but
also in whatever contains that container. Thus, all human
beings are not only on the Earth but also in the universe;
the universe is the place that is common to everything. But
the universe itself is not in a place at all, since it has
no container outside it. Thus, it is clear that place as
described by Aristotle is quite different from space as
conceived by Isaac Newton (1643–1727)—as an infinite
extension or cosmic grid (see cosmos). Newtonian space would
exist whether or not the material universe had been created.
For Aristotle, if there were no bodies, there would be no
place. Aristotle does, however, allow for the existence of a
vacuum, or “void,” but only if it is contained by actually
existing bodies.
Doctrines » Physics and metaphysics » The continuum
Spacial extension, motion, and time are often thought of as
continua—as wholes made up of a series of smaller parts.
Aristotle develops a subtle analysis of the nature of such
continuous quantities. Two entities are continuous, he says,
when there is only a single common boundary between them. On
the basis of this definition, he seeks to show that a
continuum cannot be composed of indivisible atoms. A line,
for example, cannot be composed of points that lack
magnitude. Since a point has no parts, it cannot have a
boundary distinct from itself; two points, therefore, cannot
be either adjacent or continuous. Between any two points on
a continuous line there will always be other points on the
same line.
Similar reasoning, Aristotle says, applies to time and to
motion. Time cannot be composed of indivisible moments,
because between any two moments there is always a period of
time. Likewise, an atom of motion would in fact have to be
an atom of rest. Moments or points that were indivisible
would lack magnitude, and zero magnitude, however often
repeated, can never add up to any magnitude.
Any magnitude, then, is infinitely divisible. But this
means “unendingly divisible,” not “divisible into infinitely
many parts.” However often a magnitude has been divided, it
can always be divided further. It is infinitely divisible in
the sense that there is no end to its divisibility. The
continuum does not have an infinite number of parts; indeed,
Aristotle regarded the idea of an actually infinite number
as incoherent. The infinite, he says, has only a “potential”
existence.
Doctrines » Physics and metaphysics » Motion
Motion (kinesis) was for Aristotle a broad term,
encompassing changes in several different categories. A
paradigm of his theory of motion, which appeals to the key
notions of actuality and potentiality, is local motion, or
movement from place to place. If a body X is to move from
point A to point B, it must be able to do so: when it is at
A it is only potentially at B. When this potentiality has
been realized, then X is at B. But it is then at rest and
not in motion. So motion from A to B is not simply the
actualization of a potential at A for being at B. Is it then
a partial actualization of that potentiality? That will not
do either, because a body stationary at the midpoint between
A and B might be said to have partially actualized that
potentiality. One must say that motion is an actualization
of a potentiality that is still being actualized. In the
Physics Aristotle accordingly defines motion as “the
actuality of what is in potentiality, insofar as it is in
potentiality.”
Motion is a continuum: a mere series of positions between
A and B is not a motion from A to B. If X is to move from A
to B, however, it must pass through any intermediate point
between A and B. But passing through a point is not the same
as being located at that point. Aristotle argues that
whatever is in motion has already been in motion. If X,
traveling from A to B, passes through the intermediate point
K, it must have already passed through an earlier point J,
intermediate between A and K. But however short the distance
between A and J, that too is divisible, and so on ad
infinitum. At any point at which X is moving, therefore,
there will be an earlier point at which it was already
moving. It follows that there is no such thing as a first
instant of motion.
Doctrines » Physics and metaphysics » Time
For Aristotle, extension, motion, and time are three
fundamental continua in an intimate and ordered relation to
each other. Local motion derives its continuity from the
continuity of extension, and time derives its continuity
from the continuity of motion. Time, Aristotle says, is the
number of motion with respect to before and after. Where
there is no motion, there is no time. This does not imply
that time is identical with motion: motions are motions of
particular things, and different kinds of changes are
motions of different kinds, but time is universal and
uniform. Motions, again, may be faster or slower; not so
time. Indeed, it is by the time they take that the speed of
motions is determined. Nonetheless, Aristotle says, “we
perceive motion and time together.” One observes how much
time has passed by observing the process of some change. In
particular, for Aristotle, the days, months, and years are
measured by observing the Sun, the Moon, and the stars upon
their celestial travels.
The part of a journey that is nearer its starting point
comes before the part that is nearer its end. The spatial
relation of nearer and farther underpins the relation of
before and after in motion, and the relation of before and
after in motion underpins the relation of earlier and later
in time. Thus, on Aristotle’s view, temporal order is
ultimately derived from the spatial ordering of stretches of
motion.
Doctrines » Physics and metaphysics » Matter
Change, for Aristotle, can take place in many different
categories. Local motion, as noted above, is change in the
category of place. Change in the category of quantity is
growth (or shrinkage), and change in the category of quality
(e.g., of colour) is what Aristotle calls “alteration.”
Change in the category of substance, however—a change of one
kind of thing into another—is very special. When a substance
undergoes a change of quantity or quality, the same
substance remains throughout. But does anything persist when
one kind of thing turns into another? Aristotle’s answer is
yes: matter. He says,
By matter, I mean what in itself is neither of any kind
nor of any size nor describable by any of the categories of
being. For it is something of which all these things are
predicated, and therefore its essence is different from that
of all the predicates.
An entity that is not of any kind, size, or shape and of
which nothing at all can be said may seem highly mysterious,
but this is not what Aristotle has in mind. His ultimate
matter (he sometimes calls it “prime matter”) is not in
itself of any kind. It is not in itself of any particular
size, because it can grow or shrink; it is not in itself
water or steam, because it is both of these in turn. But
this does not mean that there is any time at which it is not
of any size or any time at which it is neither water nor
steam nor anything else.
Ordinary life provides many examples of pieces of matter
changing from one kind to another. A bottle containing a
pint of cream may be found, after shaking, to contain not
cream but butter. The stuff that comes out of the bottle is
the same as the stuff that went into it; nothing has been
added and nothing taken away. But what comes out is
different in kind from what went in. It is from cases such
as this that the Aristotelian notion of matter is derived.
Doctrines » Physics and metaphysics » Form
Although Aristotle’s system makes room for forms, they
differ significantly from Forms as Plato conceived them. For
Aristotle, the form of a particular thing is not separate
(chorista) from the thing itself—any form is the form of
some thing. In Aristotle’s physics, form is always paired
with matter, and the paradigm examples of forms are those of
material substances.
Aristotle distinguishes between “substantial” and
“accidental” forms. A substantial form is a second substance
(species or kind) considered as a universal; the predicate
human, for example, is universal as well as substantial.
Thus, Socrates is human may be described as predicating a
second substance of a first substance (Socrates) or as
predicating a substantial form of a first substance. Whereas
substantial forms correspond to the category of substance,
accidental forms correspond to categories other than
substance; they are nonsubstantial categories considered as
universals. Socrates is wise, for example, may be described
as predicating a quality (wise) of a first substance or as
predicating an accidental form of a first substance.
Aristotle calls such forms “accidental” because they may
undergo change, or be gained or lost, without thereby
changing the first substance into something else or causing
it to cease to exist. Substantial forms, in contrast, cannot
be gained or lost without changing the nature of the
substance of which they are predicated. In the propositions
above, wise is an accidental form and human a substantial
form; Socrates could survive the loss of the former but not
the loss of the latter.
When a thing comes into being, neither its matter nor its
form is created. When one manufactures a bronze sphere, for
example, what comes into existence is not the bronze or the
spherical shape but the shaped bronze. Similarly in the case
of the human Socrates. But the fact that the forms of things
are not created does not mean that they must exist
independently of matter, outside space and time, as Plato
maintained. The bronze sphere derives its shape not from an
ideal Sphere but from its maker, who introduces form into
the appropriate matter in the process of his work. Likewise,
Socrates’ humanity derives not from an ideal Human but from
his parents, who introduce form into the appropriate matter
when they conceive him.
Thus, Aristotle reverses the question asked by Plato:
“What is it that two human beings have in common that makes
them both human?” He asks instead, “What makes two human
beings two humans rather than one?” And his answer is that
what makes Socrates distinct from his friend Callias is not
their substantial form, which is the same, nor their
accidental forms, which may be the same or different, but
their matter. Matter, not form, is the principle of
individuation.
Doctrines » Physics and metaphysics » Causation
In several places Aristotle distinguishes four types of
cause, or explanation. First, he says, there is that of
which and out of which a thing is made, such as the bronze
of a statue. This is called the material cause. Second,
there is the form or pattern of a thing, which may be
expressed in its definition; Aristotle’s example is the
proportion of the length of two strings in a lyre, which is
the formal cause of one note’s being the octave of another.
The third type of cause is the origin of a change or state
of rest in something; this is often called the “efficient
cause.” Aristotle gives as examples a person reaching a
decision, a father begetting a child, a sculptor carving a
statue, and a doctor healing a patient. The fourth and last
type of cause is the end or goal of a thing—that for the
sake of which a thing is done. This is known as the “final
cause.”
Although Aristotle gives mathematical examples of formal
causes, the forms whose causation interests him most are the
substantial forms of living beings. In these cases
substantial form is the structure or organization of the
being as a whole, as well as of its various parts; it is
this structure that explains the being’s life cycle and
characteristic activities. In these cases, in fact, formal
and final causes coincide, the mature realization of natural
form being the end to which the activities of the organism
tend. The growth and development of the various parts of a
living being, such as the root of a tree or the heart of a
sheep, can be understood only as the actualization of a
certain structure for the purpose of performing a certain
biological function.
Doctrines » Physics and metaphysics » Being
For Aristotle, “being” is whatever is anything whatever.
Whenever Aristotle explains the meaning of being, he does so
by explaining the sense of the Greek verb to be. Being
contains whatever items can be the subjects of true
propositions containing the word is, whether or not the is
is followed by a predicate. Thus, both Socrates is and
Socrates is wise say something about being. Every being in
any category other than substance is a property or a
modification of substance. For this reason, Aristotle says
that the study of substance is the way to understand the
nature of being. The books of the Metaphysics in which he
undertakes this investigation, VII through IX, are among the
most difficult of his writings.
Aristotle gives two superficially conflicting accounts of
the subject matter of first philosophy. According to one
account, it is the discipline “which theorizes about being
qua being, and the things which belong to being taken in
itself”; unlike the special sciences, it deals with the most
general features of beings, insofar as they are beings. On
the other account, first philosophy deals with a particular
kind of being, namely, divine, independent, and immutable
substance; for this reason he sometimes calls the discipline
“theology.”
It is important to note that these accounts are not
simply two different descriptions of “being qua being.”
There is, indeed, no such thing as being qua being; there
are only different ways of studying being. When one studies
human physiology, for example, one studies humans qua
animals—that is to say, one studies the structures and
functions that humans have in common with animals. But of
course there is no such entity as a “human qua animal.”
Similarly, to study something as a being is to study it in
virtue of what it has in common with all other things. To
study the universe as being is to study it as a single
overarching system, embracing all the causes of things
coming into being and remaining in existence.
Doctrines » Physics and metaphysics » The unmoved mover
The way in which Aristotle seeks to show that the universe
is a single causal system is through an examination of the
notion of movement, which finds its culmination in Book XI
of the Metaphysics. As noted above, motion, for Aristotle,
refers to change in any of several different categories.
Aristotle’s fundamental principle is that everything that is
in motion is moved by something else, and he offers a number
of (unconvincing) arguments to this effect. He then argues
that there cannot be an infinite series of moved movers. If
it is true that when A is in motion there must be some B
that moves A, then if B is itself in motion there must be
some C moving B, and so on. This series cannot go on
forever, and so it must come to a halt in some X that is a
cause of motion but does not move itself—an unmoved mover.
Since the motion it causes is everlasting, this X must
itself be an eternal substance. It must lack matter, for it
cannot come into existence or go out of existence by turning
into anything else. It must also lack potentiality, for the
mere power to cause motion would not ensure the sempiternity
of motion. It must, therefore, be pure actuality (energeia).
Although the revolving heavens, for Aristotle, lack the
possibility of substantial change, they possess
potentiality, because each heavenly body has the power to
move elsewhere in its diurnal round. Since these bodies are
in motion, they need a mover, and this is a motionless
mover. Such a mover could not act as an efficient cause,
because that would involve a change in itself, but it can
act as a final cause—an object of love—because being loved
does not involve any change in the beloved. The stars and
planets seek to imitate the perfection of the unmoved mover
by moving about the Earth in a circle, the most perfect of
shapes. For this to be the case, of course, the heavenly
bodies must have souls capable of feeling love for the
unmoved mover. “On such a principle,” Aristotle says,
“depend the heavens and the world of nature.”
Aristotle is prepared to call the unmoved mover “God.”
The life of God, he says, must be like the very best of
human lives. The delight that a human being takes in the
sublimest moments of philosophical contemplation is in God a
perpetual state. What, Aristotle asks, does God think of? He
must think of something—otherwise, he is no better than a
sleeping human—and whatever he is thinking of, he must think
of eternally. Either he thinks about himself, or he thinks
about something else. But the value of a thought depends on
the value of what it is a thought of, so, if God were
thinking of anything other than himself, he would be somehow
degraded. So he must be thinking of himself, the supreme
being, and his life is a thinking of thinking (noesis
noeseos).
This conclusion has been much debated. Some have regarded
it as a sublime truth; others have thought it a piece of
exquisite nonsense. Among those who have taken the latter
view, some have considered it the supreme absurdity of
Aristotle’s system, and others have held that Aristotle
himself intended it as a reductio ad absurdum. Whatever the
truth about the object of thought of the unmoved mover, it
seems clear that it does not include the contingent affairs
of individual human beings.
Thus, at the supreme point of Aristotle’s causal
hierarchy stand the heavenly movers, moved and unmoved,
which are the final cause of all generation and corruption.
And this is why metaphysics can be called by two such
different names. When Aristotle says that first philosophy
studies the whole of being, he is describing it by
indicating the field it is to explain; when he says that it
is the science of the divine, he is describing it by
indicating its ultimate principles of explanation. Thus,
first philosophy is both the science of being qua being and
also theology.
Doctrines » Philosophy of science
In his Posterior Analytics Aristotle applies the theory of
the syllogism to scientific and epistemological ends.
Scientific knowledge, he urges, must be built up out of
demonstrations. A demonstration is a particular kind of
syllogism, one whose premises can be traced back to
principles that are true, necessary, universal, and
immediately intuited. These first, self-evident principles
are related to the conclusions of science as axioms are
related to theorems: the axioms both necessitate and explain
the truths that constitute a science. The most important
axioms, Aristotle thought, would be those that define the
proper subject matter of a science (thus, among the axioms
of geometry would be the definition of a triangle). For this
reason much of the second book of the Posterior Analytics is
devoted to definition.
The account of science in the Posterior Analytics is
impressive, but it bears no resemblance to any of
Aristotle’s own scientific works. Generations of scholars
have tried in vain to find in his writings a single instance
of a demonstrative syllogism. Moreover, the whole history of
scientific endeavour contains no perfect instance of a
demonstrative science.
Doctrines » Philosophy of mind
Aristotle regarded psychology as a part of natural
philosophy, and he wrote much about the philosophy of mind.
This material appears in his ethical writings, in a
systematic treatise on the nature of the soul (De anima),
and in a number of minor monographs on topics such as
sense-perception, memory, sleep, and dreams.
For Aristotle the biologist, the soul is not—as it was in
some of Plato’s writings—an exile from a better world
ill-housed in a base body. The soul’s very essence is
defined by its relationship to an organic structure. Not
only humans but beasts and plants too have souls, intrinsic
principles of animal and vegetable life. A soul, Aristotle
says, is “the actuality of a body that has life,” where life
means the capacity for self-sustenance, growth, and
reproduction. If one regards a living substance as a
composite of matter and form, then the soul is the form of a
natural—or, as Aristotle sometimes says, organic—body. An
organic body is a body that has organs—that is to say, parts
that have specific functions, such as the mouths of mammals
and the roots of trees.
The souls of living beings are ordered by Aristotle in a
hierarchy. Plants have a vegetative or nutritive soul, which
consists of the powers of growth, nutrition, and
reproduction. Animals have, in addition, the powers of
perception and locomotion—they possess a sensitive soul, and
every animal has at least one sense-faculty, touch being the
most universal. Whatever can feel at all can feel pleasure;
hence, animals, which have senses, also have desires.
Humans, in addition, have the power of reason and thought
(logismos kai dianoia), which may be called a rational soul.
The way in which Aristotle structured the soul and its
faculties influenced not only philosophy but also science
for nearly two millennia.
Aristotle’s theoretical concept of soul differs from that
of Plato before him and René Descartes (1596–1650) after
him. A soul, for him, is not an interior immaterial agent
acting on a body. Soul and body are no more distinct from
each other than the impress of a seal is distinct from the
wax on which it is impressed. The parts of the soul,
moreover, are faculties, which are distinguished from each
other by their operations and their objects. The power of
growth is distinct from the power of sensation because
growing and feeling are two different activities, and the
sense of sight differs from the sense of hearing not because
eyes are different from ears but because colours are
different from sounds.
The objects of sense come in two kinds: those that are
proper to particular senses, such as colour, sound, taste,
and smell, and those that are perceptible by more than one
sense, such as motion, number, shape, and size. One can
tell, for example, whether something is moving either by
watching it or by feeling it, and so motion is a “common
sensible.” Although there is no special organ for detecting
common sensibles, there is a faculty that Aristotle calls a
“central sense.” When one encounters a horse, for example,
one may see, hear, feel, and smell it; it is the central
sense that unifies these sensations into perceptions of a
single object (though the knowledge that this object is a
horse is, for Aristotle, a function of intellect rather than
sense).
Besides the five senses and the central sense, Aristotle
recognizes other faculties that later came to be grouped
together as the “inner senses,” notably imagination and
memory. Even at the purely philosophical level, however,
Aristotle’s accounts of the inner senses are unrewarding.
At the same level within the hierarchy as the senses,
which are cognitive faculties, there is also an affective
faculty, which is the locus of spontaneous feeling. This is
a part of the soul that is basically irrational but is
capable of being controlled by reason. It is the locus of
desire and passion; when brought under the sway of reason,
it is the seat of the moral virtues, such as courage and
temperance. The highest level of the soul is occupied by
mind or reason, the locus of thought and understanding.
Thought differs from sense-perception and is the
prerogative, on earth, of human beings. Thought, like
sensation, is a matter of making judgments; but sensation
concerns particulars, while intellectual knowledge is of
universals. Reasoning may be practical or theoretical, and,
accordingly, Aristotle distinguishes between a deliberative
and a speculative faculty.
In a notoriously difficult passage of De anima, Aristotle
introduces a further distinction between two kinds of mind:
one passive, which can “become all things,” and one active,
which can “make all things.” The active mind, he says, is
“separable, impassible, and unmixed.” In antiquity and the
Middle Ages, this passage was the subject of sharply
different interpretations. Some—particularly among Arab
commentators—identified the separable active agent with God
or with some other superhuman intelligence.
Others—particularly among Latin commentators—took Aristotle
to be identifying two different faculties within the human
mind: an active intellect, which formed concepts, and a
passive intellect, which was a storehouse of ideas and
beliefs.
If the second interpretation is correct, then Aristotle
is here recognizing a part of the human soul that is
separable from the body and immortal. Here and elsewhere
there is detectable in Aristotle, in addition to his
standard biological notion of the soul, a residue of a
Platonic vision according to which the intellect is a
distinct entity separable from the body. No one has produced
a wholly satisfactory reconciliation between the biological
and the transcendent strains in Aristotle’s thought.
Doctrines » Ethics
The surviving works of Aristotle include three treatises on
moral philosophy: the Nicomachean Ethics in 10 books, the
Eudemian Ethics in 7 books, and the Magna moralia (Latin:
“Great Ethics”). The Nicomachean Ethics is generally
regarded as the most important of the three; it consists of
a series of short treatises, possibly brought together by
Aristotle’s son Nicomachus. In the 19th century the Eudemian
Ethics was often suspected of being the work of Aristotle’s
pupil Eudemus of Rhodes, but there is no good reason to
doubt its authenticity. Interestingly, the Nicomachean
Ethics and the Eudemian Ethics have three books in common:
books V, VI, and VII of the former are the same as books IV,
V, and VI of the latter. Although the question has been
disputed for centuries, it is most likely that the original
home of the common books was the Eudemian Ethics; it is also
probable that Aristotle used this work for a course on
ethics that he taught at the Lyceum during his mature
period. The Magna moralia probably consists of notes taken
by an unknown student of such a course.
Doctrines » Ethics » Happiness
Aristotle’s approach to ethics is teleological. If life is
to be worth living, he argues, it must surely be for the
sake of something that is an end in itself—i.e., desirable
for its own sake. If there is any single thing that is the
highest human good, therefore, it must be desirable for its
own sake, and all other goods must be desirable for the sake
of it. One popular conception of the highest human good is
pleasure—the pleasures of food, drink, and sex, combined
with aesthetic and intellectual pleasures. Other people
prefer a life of virtuous action in the political sphere. A
third possible candidate for the highest human good is
scientific or philosophical contemplation. Aristotle thus
reduces the answers to the question “What is a good life?”
to a short list of three: the philosophical life, the
political life, and the voluptuary life. This triad provides
the key to his ethical inquiry.
“Happiness,” the term that Aristotle uses to designate
the highest human good, is the usual translation of the
Greek eudaimonia. Although it is impossible to abandon the
English term at this stage of history, it should be borne in
mind that what Aristotle means by eudaimonia is something
more like well-being or flourishing than any feeling of
contentment. Aristotle argues, in fact, that happiness is
activity of the rational soul in accordance with virtue.
Human beings must have a function, because particular types
of humans (e.g., sculptors) do, as do the parts and organs
of individual human beings. This function must be unique to
humans; thus, it cannot consist of growth and nourishment,
for this is shared by plants, or the life of the senses, for
this is shared by animals. It must therefore involve the
peculiarly human faculty of reason. The highest human good
is the same as good human functioning, and good human
functioning is the same as the good exercise of the faculty
of reason—that is to say, the activity of rational soul in
accordance with virtue. There are two kinds of virtue: moral
and intellectual. Moral virtues are exemplified by courage,
temperance, and liberality; the key intellectual virtues are
wisdom, which governs ethical behaviour, and understanding,
which is expressed in scientific endeavour and
contemplation.
Doctrines » Ethics » Virtue
People’s virtues are a subset of their good qualities. They
are not innate, like eyesight, but are acquired by practice
and lost by disuse. They are abiding states, and they thus
differ from momentary passions such as anger and pity.
Virtues are states of character that find expression both in
purpose and in action. Moral virtue is expressed in good
purpose—that is to say, in prescriptions for action in
accordance with a good plan of life. It is expressed also in
actions that avoid both excess and defect. A temperate
person, for example, will avoid eating or drinking too much,
but he will also avoid eating or drinking too little. Virtue
chooses the mean, or middle ground, between excess and
defect. Besides purpose and action, virtue is also concerned
with feeling. One may, for example, be excessively concerned
with sex or insufficiently interested in it; the temperate
person will take the appropriate degree of interest and be
neither lustful nor frigid.
While all the moral virtues are means of action and
passion, it is not the case that every kind of action and
passion is capable of a virtuous mean. There are some
actions of which there is no right amount, because any
amount of them is too much; Aristotle gives murder and
adultery as examples. The virtues, besides being concerned
with means of action and passion, are themselves means in
the sense that they occupy a middle ground between two
contrary vices. Thus, the virtue of courage is flanked on
one side by foolhardiness and on the other by cowardice.
Aristotle’s account of virtue as a mean is no truism. It
is a distinctive ethical theory that contrasts with other
influential systems of various kinds. It contrasts, on the
one hand, with religious systems that give a central role to
the concept of a moral law, concentrating on the prohibitive
aspects of morality. It also differs from moral systems such
as utilitarianism that judge the rightness and wrongness of
actions in terms of their consequences. Unlike the
utilitarian, Aristotle believes that there are some kinds of
action that are morally wrong in principle.
The mean that is the mark of moral virtue is determined
by the intellectual virtue of wisdom. Wisdom is
characteristically expressed in the formulation of
prescriptions for action—“practical syllogisms,” as
Aristotle calls them. A practical syllogism consists of a
general recipe for a good life, followed by an accurate
description of the agent’s actual circumstances and
concluding with a decision about the appropriate action to
be carried out.
Wisdom, the intellectual virtue that is proper to
practical reason, is inseparably linked with the moral
virtues of the affective part of the soul. Only if an agent
possesses moral virtue will he endorse an appropriate recipe
for a good life. Only if he is gifted with intelligence will
he make an accurate assessment of the circumstances in which
his decision is to be made. It is impossible, Aristotle
says, to be really good without wisdom or to be really wise
without moral virtue. Only when correct reasoning and right
desire come together does truly virtuous action result.
Virtuous action, then, is always the result of successful
practical reasoning. But practical reasoning may be
defective in various ways. Someone may operate from a
vicious choice of lifestyle; a glutton, for example, may
plan his life around the project of always maximizing the
present pleasure. Aristotle calls such a person
“intemperate.” Even people who do not endorse such a
hedonistic premise may, once in a while, overindulge. This
failure to apply to a particular occasion a generally sound
plan of life Aristotle calls “incontinence.”
Doctrines » Ethics » Action and contemplation
The pleasures that are the domain of temperance,
intemperance, and incontinence are the familiar bodily
pleasures of food, drink, and sex. In treating of pleasure,
however, Aristotle explores a much wider field. There are
two classes of aesthetic pleasures: the pleasures of the
inferior senses of touch and taste, and the pleasures of the
superior senses of sight, hearing, and smell. Finally, at
the top of the scale, there are the pleasures of the mind.
Plato had posed the question of whether the best life
consists in the pursuit of pleasure or the exercise of the
intellectual virtues. Aristotle’s answer is that, properly
understood, the two are not in competition with each other.
The exercise of the highest form of virtue is the very same
thing as the truest form of pleasure; each is identical with
the other and with happiness. The highest virtues are the
intellectual ones, and among them Aristotle distinguished
between wisdom and understanding. To the question of whether
happiness is to be identified with the pleasure of wisdom or
with the pleasure of understanding, Aristotle gives
different answers in his main ethical treatises. In the
Nicomachean Ethics perfect happiness, though it presupposes
the moral virtues, is constituted solely by the activity of
philosophical contemplation, whereas in the Eudemian Ethics
it consists in the harmonious exercise of all the virtues,
intellectual and moral.
The Eudemian ideal of happiness, given the role it
assigns to contemplation, to the moral virtues, and to
pleasure, can claim to combine the features of the
traditional three lives—the life of the philosopher, the
life of the politician, and the life of the pleasure seeker.
The happy person will value contemplation above all, but
part of his happy life will consist in the exercise of moral
virtues in the political sphere and the enjoyment in
moderation of the natural human pleasures of body as well as
of soul. But even in the Eudemian Ethics it is “the service
and contemplation of God” that sets the standard for the
appropriate exercise of the moral virtues, and in the
Nicomachean Ethics this contemplation is described as a
superhuman activity of a divine part of human nature.
Aristotle’s final word on ethics is that, despite being
mortal, human beings must strive to make themselves immortal
as far as they can.
Doctrines » Political theory
Turning from the Ethics treatises to their sequel, the
Politics, the reader is brought down to earth. “Man is a
political animal,” Aristotle observes; human beings are
creatures of flesh and blood, rubbing shoulders with each
other in cities and communities. Like his work in zoology,
Aristotle’s political studies combine observation and
theory. He and his students documented the constitutions of
158 states—one of which, The Constitution of Athens, has
survived on papyrus. The aim of the Politics, Aristotle
says, is to investigate, on the basis of the constitutions
collected, what makes for good government and what makes for
bad government and to identify the factors favourable or
unfavourable to the preservation of a constitution.
Aristotle asserts that all communities aim at some good.
The state (polis), by which he means a city-state such as
Athens, is the highest kind of community, aiming at the
highest of goods. The most primitive communities are
families of men and women, masters and slaves. Families
combine to make a village, and several villages combine to
make a state, which is the first self-sufficient community.
The state is no less natural than the family; this is proved
by the fact that human beings have the power of speech, the
purpose of which is “to set forth the expedient and
inexpedient, and therefore likewise the just and the
unjust.” The foundation of the state was the greatest of
benefactions, because only within a state can human beings
fulfill their potential.
Government, Aristotle says, must be in the hands of one,
of a few, or of the many; and governments may govern for the
general good or for the good of the rulers. Government by a
single person for the general good is called “monarchy”; for
private benefit, “tyranny.” Government by a minority is
“aristocracy” if it aims at the state’s best interest and
“oligarchy” if it benefits only the ruling minority. Popular
government in the common interest Aristotle calls “polity”;
he reserves the word “democracy” for anarchic mob rule.
If a community contains an individual or family of
outstanding excellence, then, Aristotle says, monarchy is
the best constitution. But such a case is very rare, and the
risk of miscarriage is great, for monarchy corrupts into
tyranny, which is the worst constitution of all.
Aristocracy, in theory, is the next-best constitution after
monarchy (because the ruling minority will be the
best-qualified to rule), but in practice Aristotle preferred
a kind of constitutional democracy, for what he called
“polity” is a state in which rich and poor respect each
other’s rights and the best-qualified citizens rule with the
consent of all.
Two elements of Aristotle’s teaching affected European
political institutions for many centuries: his justification
of slavery and his condemnation of usury. Some people,
Aristotle says, think that the rule of master over slave is
contrary to nature and therefore unjust. But they are quite
wrong: a slave is someone who is by nature not his own
property but someone else’s. Aristotle agrees, however, that
in practice much slavery is unjust, and he speculates that,
if nonliving machines could be made to carry out menial
tasks, there would be no need for slaves as living tools.
Nevertheless, some people are so inferior and brutish that
it is better for them to be controlled by a master than to
be left to their own devices.
Although not himself an aristocrat, Aristotle had an
aristocratic disdain for commerce. Our possessions, he says,
have two uses, proper and improper. Money too has a proper
and an improper use; its proper use is to be exchanged for
goods and services, not to be lent out at interest. Of all
the methods of making money, “taking a breed from barren
metal” is the most unnatural.
Doctrines » Rhetoric and poetics
Rhetoric, for Aristotle, is a topic-neutral discipline that
studies the possible means of persuasion. In advising
orators on how to exploit the moods of their audience,
Aristotle undertakes a systematic and often insightful
treatment of human emotion, dealing in turn with anger,
hatred, fear, shame, pity, indignation, envy, and
jealousy—in each case offering a definition of the emotion
and a list of its objects and causes.
The Poetics is much better known than the Rhetoric,
though only the first book of the former, a treatment of
epic and tragic poetry, survives. The book aims, among other
things, to answer Plato’s criticisms of representative art.
According to the theory of Forms, material objects are
imperfect copies of original, real, Forms; artistic
representations of material objects are therefore only
copies of copies, at two removes from reality. Moreover,
drama has a specially corrupting effect, because it
stimulates unworthy emotions in its audience. In response,
Aristotle insists that imitation, so far from being the
degrading activity that Plato describes, is something
natural to humans from childhood and is one of the
characteristics that makes humans superior to animals, since
it vastly increases the scope of what they may learn.
In order to answer Plato’s complaint that playwrights are
only imitators of everyday life, which is itself only an
imitation of the real world of Forms, Aristotle draws a
contrast between poetry and history. The poet’s job is to
describe not something that has actually happened but
something that might well happen—that is to say, something
that is possible because it is necessary or likely. For this
reason, poetry is more philosophical and more important than
history, for poetry speaks of the universal, history of only
the particular. Much of what happens to people in everyday
life is a matter of sheer accident; only in fiction can one
witness character and action work themselves out to their
natural consequences.
Far from debasing the emotions, as Plato thought, drama
has a beneficial effect on them. Tragedy, Aristotle says,
must contain episodes arousing pity and fear so as to
achieve a “purification” of these emotions. No one is quite
sure exactly what Aristotle meant by katharsis, or
purification. But perhaps what he meant was that watching
tragedy helps people to put their own sorrows and worries in
perspective, because in it they observe how catastrophe can
overtake even people who are vastly their superiors.
Legacy
Since the Renaissance it has been traditional to regard the
Academy and the Lyceum as two opposite poles of philosophy.
Plato is idealistic, utopian, otherworldly; Aristotle is
realistic, utilitarian, commonsensical. (This viewpoint is
reflected in the famous depiction of Plato and Aristotle in
Raphael’s Vatican fresco The School of Athens.) In fact,
however, the doctrines that Plato and Aristotle share are
more important than those that divide them. Many
post-Renaissance historians of ideas have been less
perceptive than the commentators of late antiquity, who saw
it as their duty to construct a harmonious concord between
the two greatest philosophers of the known world.
By any reckoning, Aristotle’s intellectual achievement is
stupendous. He was the first genuine scientist in history.
He was the first author whose surviving works contain
detailed and extensive observations of natural phenomena,
and he was the first philosopher to achieve a sound grasp of
the relationship between observation and theory in
scientific method. He identified the various scientific
disciplines and explored their relationships to each other.
He was the first professor to organize his lectures into
courses and to assign them a place in a syllabus. His Lyceum
was the first research institute in which a number of
scholars and investigators joined in collaborative inquiry
and documentation. Finally, and not least important, he was
the first person in history to build up a research library,
a systematic collection of works to be used by his
colleagues and to be handed on to posterity.
Millennia later, Plato and Aristotle still have a strong
claim to being the greatest philosophers who have ever
lived. But if their contribution to philosophy is equal, it
was Aristotle who made the greater contribution to the
intellectual patrimony of the world. Not only every
philosopher but also every scientist is in his debt. He
deserves the title Dante gave him: “the master of those who
know.”
Sir Anthony J.P. Kenny
