Aristotle

Ἀριστοτέλης

Roman copy (in marble) of a Greek bronze bust of Aristotle by Lysippos (c. 330 BC), with modern alabaster mantle

Born384 BC

Stagira, Chalcidian League

Died322 BC (aged 61–62)

Chalcis, Euboea, Macedonian Empire

Education EducationPlatonic Academy Philosophical work EraAncient Greek philosophy RegionWestern philosophy SchoolPeripatetic school Notable studentsAlexander the Great, Theophrastus, Aristoxenus Main interests

• Logic
• Natural philosophy
• Metaphysics
• Ethics
• Politics
• Rhetoric
• Poetics

Notable works

• Organon
• Physics
• Metaphysics
• Nicomachean Ethics
• Politics
• Rhetoric
• Poetics

Notable ideasAristotelianism

Theoretical philosophy

• Aristotelian logic, syllogism
• Four causes
• Genus and differentia
• Hylomorphism, substance, essence, accident
• Hypokeimenon
• Potentiality and actuality
• Theory of universals
• Unmoved mover

Natural philosophy

• Aristotelian biology
• Aristotelian physics
• Common sense
• Eternity of the world
• Five wits
• Horror vacui
• Theory of elements, aether
• Rational animal

Practical philosophy

• Aristotelian ethics
• Catharsis
• Deliberative, epideictic and forensic rhetoric
• Enthymeme and Paradeigma
• Family as a model for the state
• Golden mean
• Kyklos
• Magnanimity
• Mimesis
• Natural slavery
• Intellectual virtues: sophia, episteme, nous, phronesis, techne
• Three appeals: ethos, logos, pathos
• Views on women

Aristotle[A] (Attic Greek: Ἀριστοτέλης, romanized: Aristotélēs;[B] 384–322 BC) was an ancient Greek philosopher and polymath. His writings cover a broad range of subjects spanning the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic school of philosophy in the Lyceum in Athens, he began the wider Aristotelian tradition that followed, which set the groundwork for the development of modern science.

Little is known about Aristotle’s life. He was born in the city of Stagira in northern Greece during the Classical period. His father, Nicomachus, died when Aristotle was a child, and he was brought up by a guardian. At around eighteen years old, he joined Plato’s Academy in Athens and remained there until the age of thirty seven (c. 347 BC). Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored his son Alexander the Great beginning in 343 BC. He established a library in the Lyceum, which helped him to produce many of his hundreds of books on papyrus scrolls.

Though Aristotle wrote many treatises and dialogues for publication, only around a third of his original output has survived, none of it intended for publication. Aristotle provided a complex synthesis of the various philosophies existing prior to him. His teachings and methods of inquiry have had a significant impact across the world, and remain a subject of contemporary philosophical discussion.

Aristotle’s views profoundly shaped medieval scholarship. The influence of his physical science extended from late antiquity and the Early Middle Ages into the Renaissance, and was not replaced systematically until the Enlightenment and theories such as classical mechanics were developed. He influenced Judeo-Islamic philosophies during the Middle Ages, as well as Christian theology, especially the Neoplatonism of the Early Church and the scholastic tradition of the Catholic Church.

Aristotle was revered among medieval Muslim scholars as "The First Teacher", and among medieval Christians like Thomas Aquinas as simply "The Philosopher", while the poet Dante called him "the master of those who know". He has been referred to as the first scientist. His works contain the earliest known systematic study of logic, and were studied by medieval scholars such as Peter Abelard and Jean Buridan. His influence on logic continued well into the 19th century. In addition, his ethics, although always influential, has gained renewed interest with the modern advent of virtue ethics.

Life

In general, the details of Aristotle’s life are not well-established. The biographies written in ancient times are often speculative and historians only agree on a few salient points.[C] Aristotle was born in 384 BC[D] in Stagira, Chalcidice,[2] about 55 km (34 miles) east of modern-day Thessaloniki.[3][4] He was the son of Nicomachus, the personal physician of King Amyntas of Macedon,[5] and Phaestis, a woman with origins from Chalcis, Euboea.[6] Nicomachus was said to have belonged to the medical guild of Asclepiadae and was likely responsible for Aristotle’s early interest in biology and medicine.[7] Ancient tradition held that Aristotle’s family descended from the legendary physician Asclepius and his son Machaon.[8] Both of Aristotle’s parents died when he was still at a young age and Proxenus of Atarneus became his guardian.[9] Although little information about Aristotle’s childhood has survived, he probably spent some time in the Macedonian capital, making his first connections with the Macedonian monarchy.[10]

School of Aristotle in Mieza, Macedonia, Greece

At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Plato’s Academy.[11] He became distinguished as a researcher and lecturer, earning for himself the nickname "mind of the school" by his tutor Plato.[12] In Athens, he probably experienced the Eleusinian Mysteries as he wrote when describing the sights one viewed at the Mysteries, "to experience is to learn" (παθεĩν μαθεĩν).[13] Aristotle remained in Athens for nearly twenty years before leaving in 348/47 BC after Plato’s death.[14] The traditional story about his departure records that he was disappointed with the academy’s direction after control passed to Plato’s nephew Speusippus, although it is possible that the anti-Macedonian sentiments in Athens could have also influenced his decision.[15][16] Aristotle left with Xenocrates to Assos in Asia Minor, where he was invited by his former fellow student Hermias of Atarneus; he stayed there for a few years, leaving around the time of Hermias’ death.[E] While at Assos, Aristotle and his colleague Theophrastus did extensive research in botany and marine biology, which they later continued at the near-by island of Lesbos.[17] During this time, Aristotle married Pythias, Hermias’s adoptive daughter and niece, and had a daughter whom they also named Pythias.[18]

"Aristotle tutoring Alexander" (1895) by Jean Leon Gerome Ferris

In 343/42 BC, Aristotle was invited to Pella by Philip II of Macedon to become the tutor to his thirteen-year-old son Alexander;[19] a choice perhaps influenced by the relationship of Aristotle’s family with the Macedonian dynasty.[20] Aristotle taught Alexander at the private school of Mieza, in the gardens of the Nymphs, the royal estate near Pella.[21] Alexander’s education probably included a number of subjects, such as ethics and politics,[22] as well as standard literary texts, like Euripides and Homer.[23] It is likely that during Aristotle’s time in the Macedonian court, other prominent nobles, like Ptolemy and Cassander, would have occasionally attended his lectures.[24] Aristotle encouraged Alexander toward eastern conquest, and his own attitude towards Persia was strongly ethnocentric. In one famous example, he counsels Alexander to be "a leader to the Greeks and a despot to the barbarians".[25] Alexander’s education under the guardianship of Aristotle likely lasted for only a few years, as at around the age of sixteen he returned to Pella and was appointed regent of Macedon by his father Philip.[26] During this time, Aristotle gifted Alexander an annotated copy of the Iliad, which is said to have become one of Alexander’s most prized possessions.[27] Scholars speculate that two of Aristotle’s now lost works, On kingship and On behalf of the Colonies, were composed by the philosopher for the young prince.[28] Aristotle returned to Athens for the second and final time a year after Philip II’s assassination in 336 BC.[29]

As a metic, Aristotle could not own property in Athens and thus rented a building known as the Lyceum (named after the sacred grove of Apollo Lykeios), in which he established his own school.[30] The building included a gymnasium and a colonnade (peripatos), from which the school acquired the name Peripatetic.[31] Aristotle conducted courses and research at the school for the next twelve years. He often lectured small groups of distinguished students and, along with some of them, such as Theophrastus, Eudemus, and Aristoxenus, Aristotle built a large library which included manuscripts, maps, and museum objects.[32] While in Athens, his wife Pythias died and Aristotle became involved with Herpyllis of Stagira. They had a son whom Aristotle named after his father, Nicomachus.[33] This period in Athens, between 335 and 323 BC, is when Aristotle is believed to have composed many of his philosophical works.[34] He wrote many dialogues, of which only fragments have survived. Those works that have survived are in treatise form and were not, for the most part, intended for widespread publication; they are generally thought to be lecture aids for his students. His most important treatises include Physics, Metaphysics, Nicomachean Ethics, Politics, On the Soul and Poetics. Aristotle studied and made significant contributions to "logic, metaphysics, mathematics, physics, biology, botany, ethics, politics, agriculture, medicine, dance, and theatre."[35]

Portrait bust of Aristotle; an Imperial Roman (1st or 2nd century AD) copy of a lost bronze sculpture made by Lysippos

While Alexander deeply admired Aristotle, near the end of his life, the two men became estranged having diverging opinions over issues, like the optimal administration of city-states, the treatment of conquered populations, such as the Persians, and philosophical questions, like the definition of braveness.[36] A widespread speculation in antiquity suggested that Aristotle played a role in Alexander’s death, but the only evidence of this is an unlikely claim made some six years after the death.[37] Following Alexander’s death, anti-Macedonian sentiment in Athens was rekindled. In 322 BC, Demophilus and Eurymedon the Hierophant reportedly denounced Aristotle for impiety,[38] prompting him to flee to his mother’s family estate in Chalcis, Euboea, at which occasion he was said to have stated "I will not allow the Athenians to sin twice against philosophy"[39] – a reference to Athens’s trial and execution of Socrates.[15] He died in Chalcis, Euboea[40][41] of natural causes later that same year, having named his student Antipater as his chief executor and left a will in which he asked to be buried next to his wife.[42] Aristotle left his works to Theophrastus, his successor as the head of the Lyceum, who in turn passed them down to Neleus of Scepsis in Asia Minor. There, the papers remained hidden for protection until they were purchased by the collector Apellicon. In the meantime, many copies of Aristotle’s major works had already begun to circulate and be used in the Lyceum of Athens, Alexandria, and later in Rome.[43]

Theoretical philosophy

Logic

With the Prior Analytics, Aristotle is credited with the earliest systematic study of logic,[44] and his conception of it was the dominant form of Western logic until 19th-century advances in mathematical logic.[45] Kant even stated in the Critique of Pure Reason that with Aristotle, logic reached its completion.[46]

Organon

Plato (left) and Aristotle in Raphael’s 1509 fresco, The School of Athens. Aristotle holds his Nicomachean Ethics and gestures to the earth, representing his view in immanent realism, whilst Plato gestures to the heavens, indicating his Theory of Forms, and holds his Timaeus.[47][48]

Most of Aristotle’s work is probably not in its original form, because it was most likely edited by students and later lecturers. The logical works of Aristotle were compiled into a set of six books called the Organon around 40 BC by Andronicus of Rhodes or others among his followers.[49] The books are:

1. Categories
2. On Interpretation
3. Prior Analytics
4. Posterior Analytics
5. Topics
6. On Sophistical Refutations

The order of the books (or the teachings from which they are composed) is not certain, but this list was derived from analysis of Aristotle’s writings. It goes from the basics, the analysis of simple terms in the Categories, the analysis of propositions and their elementary relations in On Interpretation, to the study of more complex forms, namely, syllogisms and demonstration (in the Analytics)[50][51] and dialectics (in the Topics and Sophistical Refutations). The first three treatises form the core of the logical theory stricto sensu: the grammar of the language of logic and the correct rules of reasoning. The Rhetoric is not conventionally included, but it states that it relies on the Topics.[52]

Syllogism

In words	In terms[G]	In equations[H]
All men are mortal. All Greeks are men.∴ All Greeks are mortal.	M a PS a MS a P

What is today called Aristotelian logic with its types of syllogism (methods of logical argument),[53] Aristotle himself would have labelled "analytics". The term "logic" he reserved to mean dialectics.[55][56]

Demonstration

Aristotle’s Posterior Analytics contains his account of demonstration, or demonstrative knowledge, what would today be considered the study of epistemology rather than logic, but which for Aristotle is deeply connected with his account of syllogism.[52] For Aristotle, knowledge is that which is necessarily the case, along with the study of causes.[52]

Metaphysics

The word "metaphysics" comes from the title of a collection of works by Aristotle bearing that title. However, Aristotle did not use that term himself, which is due to a later compiler, but instead called it "first philosophy" or theology.[57] He distinguished this as "the study of being qua being" which, as opposed to other studies of being, such as mathematics and natural science, studies that which is eternal, unchanging, and immaterial.[57] He wrote in his Metaphysics (1026a16):

If there were no other independent things besides the composite natural ones, the study of nature would be the primary kind of knowledge; but if there is some motionless independent thing, the knowledge of this precedes it and is first philosophy, and it is universal in just this way, because it is first. And it belongs to this sort of philosophy to study being as being, both what it is and what belongs to it just by virtue of being.[58]

Substance

Aristotle examines the concepts of substance (ousia) and essence (to ti ên einai, "the what it was to be") in his Metaphysics (Book VII), and he concludes that a particular substance is a combination of both matter and form, a philosophical theory called hylomorphism. In Book VIII, he distinguishes the matter of the substance as the substratum, or the stuff of which it is composed. For example, the matter of a house is the bricks, stones, timbers, etc., or whatever constitutes the potential house, while the form of the substance is the actual house, namely ‘covering for bodies and chattels’ or any other differentia that let us define something as a house. The formula that gives the components is the account of the matter, and the formula that gives the differentia is the account of the form.[59][57]

Moderate realism

Plato’s forms exist as universals, like the ideal form of an apple. For Aristotle, both matter and form belong to the individual thing (hylomorphism).

Like his teacher Plato, Aristotle’s philosophy aims at the universal. Aristotle’s ontology has the universal (katholou) exist in a lesser sense than particulars (kath’ hekaston), things in the world, whereas for Plato the universal is a realer, separately existing form which particular things merely imitate. For Aristotle, universals still exist, but are only encountered when "instantiated" in a particular substance.[57]

In addition, Aristotle disagreed with Plato about the location of universals. Where Plato spoke of the forms as existing separately from the things that participate in them, Aristotle maintained that universals are multiply located. So, according to Aristotle, the form of apple exists within each apple, rather than in the world of the forms.[57][60]

Potentiality and actuality

Concerning the nature of change (kinesis) and its causes, as he outlines in his Physics and *On Generation and Corruption (*319b–320a), he distinguishes coming-to-be (genesis, also translated as ‘generation’) from:

1. growth and diminution, which is change in quantity;
2. locomotion, which is change in space; and
3. alteration, which is change in quality. Aristotle argued that a capability like playing the flute could be acquired — the potential made actual — by learning.

Coming-to-be is a change where the substrate of the thing that has undergone the change has itself changed. In that particular change he introduces the concept of potentiality (dynamis) and actuality (entelecheia) in association with the matter and the form. Referring to potentiality, this is what a thing is capable of doing or being acted upon if the conditions are right and it is not prevented by something else. For example, the seed of a plant in the soil is potentially (dynamei) a plant, and if it is not prevented by something, it will become a plant. Potentially, beings can either ‘act’ (poiein) or ‘be acted upon’ (paschein), which can be either innate or learned. For example, the eyes possess the potentiality of sight (innate – being acted upon), while the capability of playing the flute can be possessed by learning (exercise – acting). Actuality is the fulfilment of the end of the potentiality. Because the end (telos) is the principle of every change, and potentiality exists for the sake of the end, actuality, accordingly, is the end. Referring then to the previous example, it can be said that an actuality is when a plant does one of the activities that plants do.[57]

For that for the sake of which (to hou heneka) a thing is, is its principle, and the becoming is for the sake of the end; and the actuality is the end, and it is for the sake of this that the potentiality is acquired. For animals do not see in order that they may have sight, but they have sight that they may see.[61]

In summary, the matter used to make a house has potentiality to be a house and both the activity of building and the form of the final house are actualities, which is also a final cause or end. Then Aristotle proceeds and concludes that the actuality is prior to potentiality in formula, in time and in substantiality. With this definition of the particular substance (i.e., matter and form), Aristotle tries to solve the problem of the unity of the beings, for example, "what is it that makes a man one"? Since, according to Plato there are two Ideas: animal and biped, how then is man a unity? However, according to Aristotle, the potential being (matter) and the actual one (form) are one and the same.[57][62]

Natural philosophy

Aristotle’s "natural philosophy" spans a wide range of natural phenomena including those now covered by physics, biology and other natural sciences.[63] In Aristotle’s terminology, "natural philosophy" is a branch of philosophy examining the phenomena of the natural world, and includes fields that would be regarded today as physics, biology and other natural sciences. Aristotle’s work encompassed virtually all facets of intellectual inquiry. Aristotle makes philosophy in the broad sense coextensive with reasoning, which he also would describe as "science". However, his use of the term science carries a different meaning than that covered by the term "scientific method". For Aristotle, "all science (dianoia) is either practical, poetical or theoretical" (Metaphysics 1025b25). His practical science includes ethics and politics; his poetical science means the study of fine arts including poetry; his theoretical science covers physics, mathematics and metaphysics.[63]

Physics

The four classical elements (fire, air, water, earth) of Empedocles and Aristotle illustrated with a burning log. The log releases all four elements as it is destroyed.

Five elements

In his On Generation and Corruption, Aristotle related each of the four elements proposed earlier by Empedocles, earth, water, air, and fire, to two of the four sensible qualities, hot, cold, wet, and dry. In the Empedoclean scheme, all matter was made of the four elements, in differing proportions. Aristotle’s scheme added the heavenly aether, the divine substance of the heavenly spheres, stars and planets.[64]

Element	Hot/Cold	Wet/Dry	Motion	Modern stateof matter
Earth	Cold	Dry	Down	Solid
Water	Cold	Wet	Down	Liquid
Air	Hot	Wet	Up	Gas
Fire	Hot	Dry	Up	Plasma
Aether	(divine substance)	None	Circular (in heavens)	Vacuum

Motion

Aristotle describes two kinds of motion: "violent" or "unnatural motion", such as that of a thrown stone, in the Physics (254b10), and "natural motion", such as of a falling object, in On the Heavens (300a20). In violent motion, as soon as the agent stops causing it, the motion stops also: in other words, the natural state of an object is to be at rest,[65][I] since Aristotle does not address friction.[66] With this understanding, it can be observed that, as Aristotle stated, heavy objects (on the ground, say) require more force to make them move; and objects pushed with greater force move faster.[67][J] This would imply the equation[67]

,

incorrect in modern physics.[67]

Natural motion depends on the element concerned: the aether naturally moves in a circle around the heavens,[K] while the 4 Empedoclean elements move vertically up (like fire, as is observed) or down (like earth) towards their natural resting places.[68][66][L]

Aristotle’s laws of motion. In Physics he states that objects fall at a speed proportional to their weight and inversely proportional to the density of the fluid they are immersed in.[66] This is a correct approximation for objects in Earth’s gravitational field moving in air or water.[68]

In the Physics (215a25), Aristotle effectively states a quantitative law, that the speed, v, of a falling body is proportional (say, with constant c) to its weight, W, and inversely proportional to the density,[M] ρ, of the fluid in which it is falling:[68][66]

Aristotle implies that in a vacuum the speed of fall would become infinite, and concludes from this apparent absurdity that a vacuum is not possible.[68][66] Opinions have varied on whether Aristotle intended to state quantitative laws. Henri Carteron held the "extreme view"[66] that Aristotle’s concept of force was basically qualitative,[69] but other authors reject this.[66]

Archimedes corrected Aristotle’s theory that bodies move towards their natural resting places; metal boats can float if they displace enough water; floating depends in Archimedes’ scheme on the mass and volume of the object, not, as Aristotle thought, its elementary composition.[68]

Aristotle’s writings on motion remained influential until the early modern period. John Philoponus (in late antiquity) and Galileo (in the early modern period) are said to have shown by experiment that Aristotle’s claim that a heavier object falls faster than a lighter object is incorrect.[63] A contrary opinion is given by Carlo Rovelli, who argues that Aristotle’s physics of motion is correct within its domain of validity, that of objects in the Earth’s gravitational field immersed in a fluid such as air. In this system, heavy bodies in steady fall indeed travel faster than light ones (whether friction is ignored, or not[68]), and they do fall more slowly in a denser medium.[67][N]

Isaac Newton’s "forced" motion corresponds to Aristotle’s "violent" motion with its external agent, but Aristotle’s assumption that the agent’s effect stops immediately it stops acting (e.g., the ball leaves the thrower’s hand) has awkward consequences: he has to suppose that surrounding fluid helps to push the ball along to make it continue to rise even though the hand is no longer acting on it, resulting in the Medieval theory of impetus.[68]

Four causes

Aristotle argued by analogy with woodwork that a thing takes its form from four causes: in the case of a table, the wood used (material cause), its design (formal cause), the tools and techniques used (efficient cause), and its decorative or practical purpose (final cause).[70]

Aristotle distinguished between four different "causes"(Ancient Greek: αἰτία, aitia) or explanations for why an object exists or changes:[71][72]

• The material cause describes the material out of which something is composed. Thus the material cause of a wooden table is the wood it is made of.[71]
• The formal cause is its form, i.e., the arrangement of that matter, the design of the table independent of the specific material it is made of.[71]
• The efficient cause is "the primary source", the modern definition of "cause" as either the agent or agency of particular events or states of affairs. In the case of two dominoes, when the first is knocked over it causes the second to fall.[71] In the case of an animal, this agency is a combination of how it develops from the egg, and how its body functions.[73]
• The final cause (telos) is its purpose, the reason why it exists or is done, or function that something is supposed to serve.[71] In the case of living things, it implies adaptation to a particular way of life.[73]

Optics

Aristotle was aware of Pythagorean optics.[74] He used optics in his Meteorology, treating it as a science.[75] He viewed optics as stating the laws of sight, thus combining what is now treated as physics and biology.[76] The process of see