Aristotle (Ancient Greek: Ἀριστοτέλης, romanized: Aristotélēs; 384–322 BC) was an ancient Greek philosopher and polymath. His writings span 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 Chalkidiki (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". 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.
Contents
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. Aristotle was born in 384 BC in Stagira, Chalcidice, about 55 km (34 miles) east of modern-day Thessaloniki. He was the son of Nicomachus, the personal physician of King Amyntas of Macedon, and Phaestis, a woman with origins from Chalcis, Euboea. 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. Ancient tradition held that Aristotle's family descended from the legendary physician Asclepius and his son Machaon. Both of Aristotle's parents died when he was still at a young age and Proxenus of Atarneus became his guardian. Although little information about Aristotle's childhood has survived, he probably spent some time in the Macedonian capital Pella, making his first connections with the Macedonian monarchy.
At the age of seventeen or eighteen, Aristotle moved to Athens to continue his education at Plato's Academy. He became distinguished as a researcher and lecturer, earning for himself the nickname "mind of the school" by his tutor Plato. 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). Aristotle remained in Athens for nearly twenty years before leaving in 348/47 BC after Plato's death. 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. 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. 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. During this time, Aristotle married Pythias, Hermias's adoptive daughter and niece, and had a daughter whom they also named Pythias.
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; a choice perhaps influenced by the relationship of Aristotle's family with the Macedonian dynasty. Aristotle taught Alexander at the private school of Mieza, in the gardens of the Nymphs, the royal estate near Pella. Alexander's education probably included a number of subjects, such as ethics and politics, as well as standard literary texts, like Euripides and Homer. 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. 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". 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. 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. 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. Aristotle returned to Athens for the second and final time a year after Philip II's assassination in 336 BC.
Theoretical philosophy
Logic
With the Prior Analytics, Aristotle is credited with the earliest systematic study of logic, and his conception of it was the dominant form of Western logic until 19th-century advances in mathematical logic. Kant even stated in the Critique of Pure Reason that with Aristotle, logic reached its completion.
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. The books are:
Categories
On Interpretation
Prior Analytics
Posterior Analytics
Topics
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) 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.
What is today called Aristotelian logic with its types of syllogism (methods of logical argument), Aristotle himself would have labelled "analytics". The term "logic" he reserved to mean dialectics.
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. For Aristotle, knowledge is that which is necessarily the case, along with the study of causes.
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. 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. 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.
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.
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.
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.
Natural philosophy
Aristotle's "natural philosophy" spans a wide range of natural phenomena including those now covered by physics, biology and other natural sciences. 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.
Physics
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.
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, since Aristotle does not address friction. 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. This would imply the equation
F
=
m
v
{\displaystyle F=mv}
,
incorrect in modern physics.
Natural motion depends on the element concerned: the aether naturally moves in a circle around the heavens, while the 4 Empedoclean elements move vertically up (like fire, as is observed) or down (like earth) towards their natural resting places.
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, ρ, of the fluid in which it is falling:
v
=
c
W
Astronomy
In astronomy, Aristotle refuted Democritus's claim that the Milky Way was made up of "those stars which are shaded by the earth from the sun's rays," pointing out partly correctly that if "the size of the sun is greater than that of the earth and the distance of the stars from the earth many times greater than that of the sun, then... the sun shines on all the stars and the earth screens none of them." He also wrote descriptions of comets, including the Great Comet of 371 BC.
Geology and natural sciences
Aristotle was one of the first people to record any geological observations. He stated that geological change was too slow to be observed in one person's lifetime.
The geologist Charles Lyell noted that Aristotle described such change, including "lakes that had dried up" and "deserts that had become watered by rivers", giving as examples the growth of the Nile delta since the time of Homer, and "the upheaving of one of the Aeolian islands, previous to a volcanic eruption."
Meteorologica lends its name to the modern study of meteorology, but its modern usage diverges from the content of Aristotle's ancient treatise on meteors. The ancient Greeks did use the term for a range of atmospheric phenomena, but also for earthquakes and volcanic eruptions. Aristotle proposed that the cause of earthquakes was a gas or vapour (anathymiaseis) that was trapped inside the earth and trying to escape, following other Greek authors Anaxagoras, Empedocles and Democritus.
Aristotle also made many observations about the hydrologic cycle. For example, he made some of the earliest observations about desalination: he observed early – and correctly – that when seawater is heated, freshwater evaporates and that the oceans are then replenished by the cycle of rainfall and river runoff ("I have proved by experiment that salt water evaporated forms fresh and the vapour does not when it condenses condense into sea water again.")
Biology
Aristotle was the first person to study biology systematically, and biology forms a large part of his writings. He spent two years observing and describing the zoology of Lesbos and the surrounding seas, including in particular the Pyrrha lagoon in the centre of Lesbos. His data in History of Animals, Generation of Animals, Movement of Animals, and Parts of Animals are from his own observations, statements by knowledgeable people such as beekeepers and fishermen, and accounts by travellers. His apparent emphasis on animals rather than plants is a historical accident: his works on botany have been lost, but two books on plants by his pupil Theophrastus have survived.
Aristotle reports on sea life from observation on Lesbos and the catches of fishermen. He describes the catfish, electric ray, and frogfish, as well as cephalopods such as the octopus and paper nautilus. His description of the hectocotyl arm of cephalopods, used in sexual reproduction, was widely disbelieved until the 19th century. He gives accurate descriptions of the four-chambered stomachs of ruminants, and of the ovoviviparous embryological development of the hound shark.
He notes that an animal's structure is well matched to function so the heron has a long neck, long legs, and a sharp spear-like beak, whereas ducks have short legs and webbed feet. Darwin, too, noted such differences, but unlike Aristotle used the data to come to the theory of evolution. Aristotle's writings can seem to imply evolution, but Aristotle saw mutations or hybridizations as rare accidents, distinct from natural causes. He was thus critical of Empedocles's theory of a "survival of the fittest" origin of living things and their organs, and ridiculed the idea that accidents could lead to orderly results. In modern terms, he nowhere says that different species can have a common ancestor, that one kind can change into another, or that kinds can become extinct.
Aristotle did not do experiments in the modern sense. He made observations, or at most investigative procedures like dissection. In Generation of Animals, he opens a fertilized hen's egg to see the embryo's heart beating inside.
Instead, he systematically gathered data, discovering patterns common to whole groups of animals, and inferring possible causal explanations from these. This style is common in modern biology when large amounts of data become available in a new field, such as genomics. This sets out testable hypotheses and constructs a narrative explanation of what is observed. In this sense, Aristotle's biology is scientific.
Psychology
Aristotle's psychology, in his treatise On the Soul (peri psychēs), posits three kinds of soul (psyches): the vegetative, sensitive, and rational. Humans have all three. The vegetative soul is concerned with growth and nourishment. The sensitive soul experiences sensations and movement. The uniquely human, rational soul receives forms of things and compares them using the nous (intellect) and logos (reason).
For Aristotle, the soul is the form of a living being. Because all beings are composites of form and matter, the form of living beings is that which endows them with what is specific to living beings, e.g., the ability to initiate movement. In contrast to earlier philosophers, but in accordance with the Egyptians, he placed the rational soul in the heart. Aristotle distinguished sensation and thought, unlike previous philosophers except for Alcmaeon.
In On the Soul, Aristotle criticizes Plato's theory of the soul and develops his own in response. Firstly he criticises Plato's Timaeus which holds the soul takes up space and can come into physical contact with bodies. 20th-century scholarship held that Aristotle had here misinterpreted Plato. Aristotle also argued that Plato's view of reincarnation entails that a soul and its body can be mis-matched; in principle, Aristotle alleges, any soul can go with any body, according to Plato's theory.
According to Aristotle in On the Soul, memory is the ability to hold a perceived experience in the mind and to distinguish between the internal "appearance" and a past occurrence. A memory is a mental picture (phantasm) that can be recovered. An impression is left on a semi-fluid bodily organ that undergoes changes in order to make a memory. A memory occurs when stimuli such as sights or sounds are so complex that the nervous system cannot receive them all at once. These changes are the same as those involved in sensation, 'common sense', and thinking.
Aristotle uses the term 'memory' for the actual retaining of an experience in the impression that develops from sensation, and for the intellectual anxiety that comes with the impression because it is formed at a particular time and processing specific contents. Memory is of the past, prediction is of the future, and sensation is of the present. Retrieval of impressions cannot be performed suddenly. A transitional channel is needed and located in past experiences, both for previous experience and present experience.
Practical philosophy
Aristotle's practical philosophy covers areas such as ethics, politics, economics, and rhetoric.
Ethics
Aristotle was a virtue ethicist who considered ethics to be a practical rather than theoretical study, i.e., one aimed at becoming good and doing good rather than knowing for its own sake. He wrote several treatises on ethics, most notably including the Nicomachean Ethics.
Aristotle taught that virtue has to do with the proper function (ergon) of a thing. An eye is only a good eye in so much as it can see because the proper function of an eye is sight. Aristotle reasoned that humans must have a function specific to humans, and that this function must be an activity of the psuchē (soul) in accordance with reason (logos). Aristotle identified such an optimum activity (the virtuous mean, between the accompanying vices of excess or deficiency) of the soul as the aim of all human deliberate action, eudaimonia, generally translated as "happiness" or sometimes "well-being". To have the potential of ever being happy in this way necessarily requires a good character (ēthikē aretē), often translated as moral or ethical virtue or excellence.
Aristotle taught that to achieve a virtuous and potentially happy character requires a first stage of having the fortune to be habituated, not deliberately, but by teachers, and experience, leading to a later stage in which one consciously chooses to do the best things, becoming the phronimos or virtuous man. When the best people come to live life this way their practical wisdom (phronesis) and their intellect (nous) can develop with each other towards the highest possible human virtue, the wisdom of an accomplished theoretical or speculative thinker, or in other words, a philosopher.
Politics
In addition to his works on ethics, which address the individual, Aristotle addressed the city in his work titled Politics. Aristotle considered the city to be a natural community. Moreover, he considered the city to be prior in importance to the family, which in turn is prior to the individual, "for the whole must of necessity be prior to the part". He famously stated that "man is by nature a political animal" and argued that humanity's defining factor among others in the animal kingdom is its rationality. Aristotle conceived of politics as being like an organism rather than like a machine, and as a collection of parts, none of which can exist without the others. Aristotle's conception of the city is organic, and he is considered one of the first to conceive of the city in this manner.
The common modern understanding of a political community as a modern state is quite different from Aristotle's understanding. Although he was aware of the existence and potential of larger empires, the natural community according to Aristotle was the city (polis) which functions as a political "community" or "partnership" (koinōnia). The aim of the city is not just to avoid injustice or for economic stability, but rather to allow at least some citizens the possibility to live a good life, and to perform beautiful acts: "The political partnership must be regarded, therefore, as being for the sake of noble actions, not for the sake of living together." This is distinguished from modern approaches, beginning with social contract theory, according to which individuals leave the state of nature because of "fear of violent death" or its "inconveniences".
In Protrepticus, the character 'Aristotle' states:
For we all agree that the most excellent man should rule, i.e., the supreme by nature, and that the law rules and alone is authoritative; but the law is a kind of intelligence, i.e., a discourse based on intelligence. And again, what standard do we have, what criterion of good things, that is more precise than the intelligent man? For all that this man will choose, if the choice is based on his knowledge, are good things and their contraries are bad. And since everybody chooses most of all what conforms to their own proper dispositions (a just man choosing to live justly, a man with bravery to live bravely, likewise a self-controlled man to live with self-control), it is clear that the intelligent man will choose most of all to be intelligent; for this is the function of that capacity. Hence it's evident that, according to the most authoritative judgment, intelligence is supreme among goods.
Economics
Aristotle made substantial contributions to economic thought, especially to thought in the Middle Ages. In Politics, Aristotle addresses the city, property, and trade. His response to criticisms of private property, in Lionel Robbins's view, anticipated later proponents of private property among philosophers and economists, as it related to the overall utility of social arrangements. Aristotle believed that although communal arrangements may seem beneficial to society, and that although private property is often blamed for social strife, such evils in fact come from human nature. In Politics, Aristotle offers one of the earliest accounts of the origin of money. Money came into use because people became dependent on one another, importing what they needed and exporting the surplus. For the sake of convenience, people then agreed to deal in something that is intrinsically useful and easily applicable, such as iron or silver.
Aristotle's discussions on retail and interest was a major influence on economic thought in the Middle Ages. He had a low opinion of retail, believing that contrary to using money to procure things one needs in managing the household, retail trade seeks to make a profit. It thus uses goods as a means to an end, rather than as an end unto itself. He believed that retail trade was in this way unnatural. Similarly, Aristotle considered making a profit through interest unnatural, as it makes a gain out of the money itself, and not from its use.
Aristotle gave a summary of the function of money that was perhaps remarkably precocious for his time. He wrote that because it is impossible to determine the value of every good through a count of the number of other goods it is worth, the necessity arises of a single universal standard of measurement. Money thus allows for the association of different goods and makes them "commensurable". He goes on to state that money is also useful for future exchange, making it a sort of security. That is, "if we do not want a thing now, we shall be able to get it when we do want it".
Rhetoric
Aristotle's Rhetoric proposes that a speaker can use three basic kinds of appeals to persuade his audience: ethos (an appeal to the speaker's character), pathos (an appeal to the audience's emotion), and logos (an appeal to logical reasoning). He also categorizes rhetoric into three genres: epideictic (ceremonial speeches dealing with praise or blame), forensic (judicial speeches over guilt or innocence), and deliberative (speeches calling on an audience to decide on an issue). Aristotle also outlines two kinds of rhetorical proofs: enthymeme (proof by syllogism) and paradeigma (proof by example).
Poetics
Aristotle writes in his Poetics that epic poetry, tragedy, comedy, dithyrambic poetry, painting, sculpture, music, and dance are all fundamentally acts of mimesis ("imitation"), each varying in imitation by medium, object, and manner. He applies the term mimesis both as a property of a work of art and also as the product of the artist's intention and contends that the audience's realisation of the mimesis is vital to understanding the work itself. Aristotle states that mimesis is a natural instinct of humanity that separates humans from animals and that all human artistry "follows the pattern of nature". Because of this, Aristotle believed that each of the mimetic arts possesses what Stephen Halliwell calls "highly structured procedures for the achievement of their purposes." For example, music imitates with the media of rhythm and harmony, whereas dance imitates with rhythm alone, and poetry with language. The forms also differ in their object of imitation. Comedy, for instance, is a dramatic imitation of men worse than average; whereas tragedy imitates men slightly better than average. Lastly, the forms differ in their manner of imitation – through narrative or character, through change or no change, and through drama or no drama.
While it is believed that Aristotle's Poetics originally comprised two books – one on comedy and one on tragedy – only the portion that focuses on tragedy has survived. Aristotle taught that tragedy is composed of six elements: plot-structure, character, style, thought, spectacle, and lyric poetry. The characters in a tragedy are merely a means of driving the story; and the plot, not the characters, is the chief focus of tragedy. Tragedy is the imitation of action arousing pity and fear, and is meant to effect the catharsis of those same emotions. Aristotle concludes Poetics with a discussion on which, if either, is superior: epic or tragic mimesis. He suggests that because tragedy possesses all the attributes of an epic, possibly possesses additional attributes such as spectacle and music, is more unified, and achieves the aim of its mimesis in shorter scope, it can be considered superior to epic. Aristotle was a keen systematic collector of riddles, folklore, and proverbs; he and his school had a special interest in the riddles of the Delphic Oracle and studied the fables of Aesop.
Legacy
More than 2300 years after his death, Aristotle remains one of the most influential people who ever lived. He contributed to almost every field of human knowledge then in existence, and was the founder of many new fields. According to the philosopher Bryan Magee, "it is doubtful whether any human being has ever known as much as he did". Aristotle has been regarded as the first scientist.
Aristotle was the founder of term logic, pioneered the study of zoology, and benefited future scientists and philosophers through his contributions to the scientific method. Taneli Kukkonen, observes that his achievement in founding two sciences is unmatched, and his reach in influencing "every branch of intellectual enterprise" including Western ethical and political theory, theology, rhetoric, and literary analysis is equally long. As a result, Kukkonen argues, any analysis of reality today "will almost certainly carry Aristotelian overtones ... evidence of an exceptionally forceful mind." Kukkonen writes that "in the best 20th-century scholarship Aristotle comes alive as a thinker wrestling with the full weight of the Greek philosophical tradition." Jonathan Barnes wrote that "an account of Aristotle's intellectual afterlife would be little less than a history of European thought".
Aristotle has been called the father of logic, biology, political science, zoology, embryology, natural law, scientific method, rhetoric, psychology, realism, criticism, individualism, teleology, and meteorology.
What follows is an overview of the transmission and influence of his texts and ideas into the modern era.
Ancient
The immediate influence of Aristotle's work was felt as the Lyceum grew into the Peripatetic school. Aristotle's students included Aristoxenus, Dicaearchus, Demetrius of Phalerum, Eudemos of Rhodes, Harpalus, Hephaestion, Mnason of Phocis, Nicomachus, and Theophrastus.
Aristotle's pupil and successor, Theophrastus, wrote the History of Plants, a pioneering work in botany. Some of his technical terms remain in use, such as carpel from carpos, fruit, and pericarp, from pericarpion, seed chamber. Theophrastus was much less concerned with formal causes than Aristotle was, instead pragmatically describing how plants functioned.
Under the Ptolemies, the first medical teacher at Alexandria, Herophilus of Chalcedon, corrected Aristotle, placing intelligence in the brain, and connected the nervous system to motion and sensation. Herophilus also distinguished between veins and arteries, noting that the latter pulse while the former do not.
In antiquity, Aristotle's writings were divisible into two groups; the "exoteric" works, intended for the public, and the "esoteric" treatises, for use within the Lyceum school. However, all of the works of Aristotle that have survived from antiquity through medieval manuscript transmission are the technical philosophical treatises from within Aristotle's school, which were compiled in the 1st century BC by Andronicus of Rhodes out of a series of smaller, separate works into the more cohesive, larger works as they are known today.
The primary way that ancient philosophers in the Roman empire engaged with Aristotle's technical work was via philosophical commentary; interpretation and explication of the text of Aristotle along with their own synthesis and views on the topics discussed by Aristotle. The peripatetic commentary tradition began with Boethus of Sidon in the 1st century BC and reached its peak at the end of the 2nd century AD with Alexander of Aphrodisias, who was appointed to the official Imperial chair of Aristotelian philosophy established by Marcus Aurelius, many of whose commentaries still survive.
In the 3rd century, Neoplatonism emerged as the dominant philosophical school. The Neoplatonists saw all subsequent philosophical systems after Plato, including Aristotle's, as developments on Plato's philosophy, and sought to explain how Plato and Aristotle were in agreement, even on subjects where they appeared to disagree, and included Aristotle's logical and physical works in their school curriculum as introductory works that needed to be mastered before the study of Plato himself. This study program began with the Categories, which the Neoplatonist philosopher Porphyry of Tyre wrote an introduction to, called Isagoge, which went on to influence subsequent philosophy in late antiquity and the medieval period. Later Neoplatonists in Athens and Alexandria including Syrianus, Ammonius Hermiae, Olympiodorus the Younger and Simplicius of Cilicia wrote further commentaries on Aristotle from a Platonist perspective which are still extant, with Simplicius compiling many of the lost works of his predecessors into massive commentaries that survey the entire Neoplatonic tradition.
Medieval
After a hiatus of several centuries, formal commentary by Eustratius and Michael of Ephesus reappeared in the late eleventh and early twelfth centuries, apparently sponsored by Anna Comnena. Byzantine philosophers also filled in the gaps in the commentaries that had survived down to their time; Alexander of Aphrodisias' commentary on the Metaphysics, of which only the first five books survived, was completed by Michael of Ephesus, who also wrote a commentary on the Sophistical Refutations, the only work of the Organon not to have a commentary, and Michael of Ephesus and Eustratius compiled a number of fragmentary commentaries on the Nicomachean Ethics which they supplemented with their own interpretations. Michael of Ephesus wrote commentaries on the works of Aristotle's animal biology and the Politics, completing the series of commentaries on Aristotle's extant works.
Aristotle's works underwent a revival in the Abbasid Caliphate. Translated into Arabic, Aristotle's logic, ethics, and natural philosophy inspired early Islamic scholars. Aristotle is considered the most influential figure in the history of Arabic philosophy and was revered in early Islamic theology. Most surviving works of Aristotle, as well as some of the original Greek commentaries, were translated into Arabic and studied by Muslim philosophers, scientists, and scholars. Through commentaries and critical engagements, figures like Al-Kindi, Al-Farabi, Ibn Sina (Avicenna), and Averroes breathed new life into Aristotle's ideas. They harmonized his logic with Islamic theology, employed his scientific methodology to explore the natural world, and reinterpreted his ethics within the framework of Islamic morality. Islamic thinkers embraced Aristotle's rigorous methods while challenging his conclusions where they diverged from their religious beliefs, which later influenced Thomas Aquinas and other Western Christian scholastic philosophers. Medieval Muslim scholars described Aristotle as the "First Teacher". The title was later used by Western philosophers (as in Dante's poem) who were influenced by the tradition of Islamic philosophy.
Moses Maimonides (considered to be the foremost intellectual figure of medieval Judaism) adopted Aristotelianism from the Islamic scholars and based his Guide for the Perplexed on it; the work became the basis of Jewish scholastic philosophy. Maimonides also considered Aristotle to be the greatest philosopher that ever lived, and styled him as the "chief of the philosophers". Also, in his letter to Samuel ibn Tibbon, Maimonides observes that there is no need for Samuel to study the writings of philosophers who preceded Aristotle because the works of the latter are "sufficient by themselves and [superior] to all that were written before them. His intellect, Aristotle's is the extreme limit of human intellect, apart from him upon whom the divine emanation has flowed forth to such an extent that they reach the level of prophecy, there being no level higher".
Modern era
In the early modern period, scientists such as William Harvey in England and Galileo Galilei in Italy reacted against the theories of Aristotle and other classical era thinkers like Galen, establishing new theories based to some degree on observation and experiment. Harvey demonstrated the circulation of the blood, establishing that the heart functioned as a pump rather than being the seat of the soul and the controller of the body's heat, as Aristotle thought. Galileo used more doubtful arguments to displace Aristotle's physics, proposing that bodies all fall at the same speed whatever their weight.
The English mathematician George Boole fully accepted Aristotle's logic, but decided "to go under, over, and beyond" it with his system of algebraic logic in his 1854 book The Laws of Thought. This gives logic a mathematical foundation with equations, enables it to solve equations as well as check validity, and allows it to handle a wider class of problems by expanding propositions of any number of terms, not just two.
Charles Darwin regarded Aristotle as the most important contributor to the subject of biology. In an 1882 letter he wrote that "Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle". Also, in later editions of the book "On the Origin of Species', Darwin traced evolutionary ideas as far back as Aristotle; the text he cites is a summary by Aristotle of the ideas of the earlier Greek philosopher Empedocles.
The philosopher Bertrand Russell claimed that "almost every serious intellectual advance has had to begin with an attack on some Aristotelian doctrine". Russell called Aristotle's ethics "repulsive", and labelled his logic "as definitely antiquated as Ptolemaic astronomy". Russell stated that these errors make it difficult to do historical justice to Aristotle, until one remembers what an advance he made upon all of his predecessors.
The Dutch historian of science Eduard Jan Dijksterhuis writes that Aristotle and his predecessors showed the difficulty of science by "proceed[ing] so readily to frame a theory of such a general character" on limited evidence from their senses. In 1985, the biologist Peter Medawar could still state in "pure seventeenth century" tones that Aristotle had assembled "a strange and generally speaking rather tiresome farrago of hearsay, imperfect observation, wishful thinking and credulity amounting to downright gullibility".
Depictions in art
Paintings
Aristotle has been depicted by major artists including Lucas Cranach the Elder, Justus van Gent, Raphael, Paolo Veronese, Jusepe de Ribera, Rembrandt, and Francesco Hayez over the centuries. Among the best-known depictions is Raphael's fresco The School of Athens, in the Vatican's Apostolic Palace, where the figures of Plato and Aristotle are central to the image, at the architectural vanishing point, reflecting their importance. Rembrandt's Aristotle with a Bust of Homer, too, is a celebrated work, showing the knowing philosopher and the blind Homer from an earlier age: as the art critic Jonathan Jones writes, "this painting will remain one of the greatest and most mysterious in the world, ensnaring us in its musty, glowing, pitch-black, terrible knowledge of time."
Eponyms
The Aristotle Mountains in Antarctica are named after Aristotle. He was the first person known to conjecture, in his book Meteorology, the existence of a landmass in the southern high-latitude region, which he called Antarctica. Aristoteles is a crater on the Moon bearing the classical form of Aristotle's name. (6123) Aristoteles, an asteroid in the main asteroid belt, also bears the classical form of his name.