Aristotle Stagiritis Was A Greek Philosopher Philosophy Essay




Historical Background…






Contributions In Different Fields



Philosophy Of Aristotle…



Aristotle’s Logic…



Analytics and the Organon…



Aristotle’s Achievements…









(384 BC – 322 BC)



Aristotle Stagiritis was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology. Together with Plato and Socrates (Plato's teacher), Aristotle is one of the most important founding figures in Western philosophy. Aristotle's writings were the first to create a comprehensive system of Western philosophy, encompassing morality and aesthetics, logic and science, politics and metaphysics.

Aristotle's views on the physical sciences profoundly shaped medieval scholarship, and their influence extended well into the Renaissance, although they were ultimately replaced by Newtonian physics. In the zoological sciences, some of his observations were confirmed to be accurate only in the 19th century. His works contain the earliest known formal study of logic, which was incorporated in the late 19th century into modern formal logic. In metaphysics, Aristotelianism had a profound influence on philosophical and theological thinking in the Islamic and Jewish traditions in the middle Ages, and it continues to influence Christian theology, especially the scholastic tradition of the Catholic Church. His ethics, though always influential, gained renewed interest with the modern advent of virtue ethics. All aspects of Aristotle's philosophy continue to be the object of active academic study today. Though Aristotle wrote many elegant treatises and dialogues Cicero described his literary style as "a river of gold",it is thought that the majority of his writings are now lost and only about one-third of the original works have survived

Historical Backgroundimages.jpg

Aristotle was born in Stagira in north Greece, the son of Nichomachus, the court physician to the Macedonian royal family. He was trained first in medicine, and then in 367 he was sent to Athens to study philosophy with Plato. He stayed at Plato's Academy until about 347 -- the picture at the top of this page, taken from Raphael's fresco The School of Athens, shows Aristotle and Plato (Aristotle is on the. right). Though a brilliant pupil, Aristotle opposed some of Plato's teachings, and when Plato died, Aristotle was not appointed head of the Academy. After leaving Athens, Aristotle spent some time traveling, and possibly studying biology, in Asia Minor (now Turkey) and its islands. He returned to Macedonia in 338 to tutor Alexander the Great; after Alexander conquered Athens, Aristotle returned to Athens and set up a school of his own, known as the Lyceum. After Alexander's death, Athens rebelled against Macedonian rule, and Aristotle's political situation became precarious. To avoid being put to death, he fled to the island of Euboea, where he died soon after.

When Plato died in 347, the Academy came under the control of his nephew Speusippus, who favored mathematical aspects of Platonism that Aristotle, who was more interested in biology, found uncongenial. Perhaps for this reason - but more likely because of growing anti-Macedonian sentiment in Athens - Aristotle decided to leave. He accepted the invitation of Hermeias, his friend and a former fellow student in the Academy, to join his philosophical circle on the coast of Asia Minor in Assos, where Hermeias (a former slave) had become ruler. Aristotle remained there for three years. During this period he married Hermeias’s niece, Pythias, with whom he had a daughter, also named Pythias.

In 345, Aristotle moved to Mytilene, on the nearby island of Lesbos, where he joined another former Academic, Theophrastus, who was a native of the island. Theophrastus, at first Aristotle’s pupil and then his closest colleague, remained associated with him until Aristotle’s death. While they were on Lesbos the biological research of Aristotle and Theophrastus flourished. In 343, Philip of Macedon invited Aristotle to his court to serve as tutor to his son Alexander, then thirteen years old. What instruction Aristotle gave to the young man who was to become Alexander the Great is not known, but it seems likely that Aristotle’s own interest in politics increased during his stay at the Macedonian court. In 340 Alexander was appointed regent for his father and his studies with Aristotle ended. academos.jpg

Plato’s academy: 387 BC-529 AD

The events of the next five years are uncertain. Perhaps Aristotle stayed at the court; perhaps he went back to Stagira. But in 335, after the death of Philip, he returned to Athens for his second long sojourn. Just outside the city he rented some buildings and established his own school, the Lyceum, where he lectured, wrote, and discussed philosophy with his pupils and associates. Under his direction, they carried out research on biological and other philosophical and scientific topics. Theophrastus worked on botany, Aristoxenus on music; Eudemus wrote a history of mathematics and astronomy, Meno of medicine, and Theophrastus of physics, cosmology, and psychology. In addition, Aristotle and his group produced a monumental account of the constitutions of 158 Greek city-states - an account Aristotle draws on in his own Politics.

While he was in Athens, Aristotle’s wife Pythias died. He subsequently began a union with a woman named Herpyllis, like Aristotle a native of Stagira. Although they apparently never married, they had a son, whom they named Nicomachus, after Aristotle’s father.

Aristotle’s work during his twelve or thirteen years at the Lyceum was prodigious. Most of his surviving works were probably written during this period. But when Alexander died in 323, Athens once again became a hostile environment for a Macedonian, and Aristotle was accused of impiety (the same charge that had been leveled against both Anaxagoras and Socrates). Leaving the Lyceum in the hands of Theophrastus, Aristotle fled northward to the Macedonian stronghold of Chalcis (his mother’s birthplace); he is said to have remarked that he would "not allow the Athenians to sin twice against philosophy." Removed from the cultural center of Athens, he lamented his isolation and died in 322 at the age of sixty-two.

Of Aristotle’s writings, only about one fifth to one quarter have survived. Still, the great variety of subjects that they cover provides a good indication of the range and depth of his interests. The notorious difficulty these writings pose for the contemporary reader is in part explained by the nature of the works themselves. Far from being polished pieces of prose intended for publication, they are for the most part working papers and lecture notes, terse and compressed often to the point of unintelligibility. (Ancient sources tell us that in his published works - now lost - Aristotle displayed an exemplary literary style, and there are occasional glimpses of it in the surviving works.)

Aristotle was above all driven by a desire for knowledge and understanding in every possible realm. His works are teeming with detailed observations about the natural world as well as abstract speculations of the most general sort. As both a scientist and a philosopher, Aristotle could easily make the transition from describing the feeding behavior of eels and limpets to theorizing about the divine intellect that is the uncaused cause of everything else in the universe. But his philosophical and scientific interests are rooted in the natural world - about one quarter of the surviving works deal with topics in biology. This he combined with an unshakeable confidence in the ability of the human mind, aided by the system of deductive logic he invented and by close and detailed observation of natural phenomena, to comprehend the fundamental nature of objective reality.

Aristotle did not suppose that he was the first person to attempt this task. He was a keen student of the writings of his scientific and philosophical predecessors. The influence of Plato’s thought is apparent throughout Aristotle’s works, even where he disagrees with his teacher most. He pays a great deal of attention to the Presocratics, seldom agreeing with them, but often crediting them with important (albeit usually partial) insights. His typical approach to a subject is to review its history and then, making what use he can of the received opinions, to set out his own account. Often his position is a kind of compromise that incorporates the best features while avoiding the excesses of rival schemes that are too extreme.

All of the sciences can be divided into three branches: theoretical, practical, and productive. Whereas practical sciences, such as ethics and politics, are concerned with human action, and productive sciences with making things, theoretical sciences, such as theology, mathematics, and the natural sciences, aim at truth and are pursued for their own sake. Aristotle was unique in pursuing all three. His Rhetoric and Poetics, which provide the foundation for the study of speech and literary theory, are his contributions to the productive sciences. The Ethics and Politics are devoted to the practical sciences. In the remainder of his works, Aristotle directs his attention to the theoretical sciences.

Aristotle has had a profound influence on the history of philosophy. From late antiquity through the middle ages, it was standard procedure for philosophers to couch their own writings in the form of commentaries on his works. His logic was so thoroughly accepted that the subject remained virtually unchanged for the next two millennia. His concepts of subject and predicate, matter and form, essence and accident, species and genus, among others, have become a standard part of the philosophical vernacular. Although many of his ideas have been discredited or superseded, much of what he has to say remains relevant to issues of vital contemporary interest. In terms of the breadth of his intellectual curiosity and the vastness of his influence, Aristotle is without equal in the history of human thought.

Aristotle’s Concepts

In his earliest ontological writings, Aristotle maintains that individual biological specimens - this man, or that tree - are the primary substances . The species to which they belong, man and tree, are substances in a secondary sense. But he subsequently begins to raise the question of what it is that makes this man or that tree a substance - what the substance of these things is, as he puts it. He intimates that the answer to this question will tell us what primary substance is. His convoluted and difficult investigation of this question leads him to the conclusion that it is form or essence that is primary substance. This suggests a tilt in the direction of Platonism, but Aristotle insists that his answer is different from Plato’s. For on his view Platonic forms are separate from and independent of their material instantiations, whereas Aristotelian essences in some sense are not. Still, much remains unclear about Aristotle’s answer. For example, there is no consensus among scholars about whether Aristotle thought of essences as being particular (so that each individual horse has its own unique essence) or specific (in which case the essence of all horses will be the same).

Aristotle’s universe is finite, eternal, and geocentric: a stationary earth surrounded by concentric spheres that carry the sun, moon, planets, and stars in their circular orbits about the earth. Everything below the sphere of the moon is made of four fundamental elements - earth, water, air, and fire - that interact and are capable of transforming into one another. Each element is characterized by a pair of properties from among the contraries hot, cold, wet, and dry. Earth is cold and dry, water cold and wet, air hot and wet, fire hot and dry. The heavenly bodies are made of a different kind of matter altogether, a fifth element .Each element has a natural place and a natural movement. The four sublunary elements tend to move in a straight line, earth downward toward the center of the universe, fire toward the extreme, and air and water toward intermediate places. Once in its natural place, each of these four remains at rest unless something else causes it to move. The natural movement of the fifth element in the heavens is circular and eternal. All of this movement and change is ultimately explained in terms of an "unmoved mover" - a cause of change that is itself uncaused and outside of the universe.

It is the job of natural science to study things whose nature it is to undergo change. In the face of influential Parmenidean arguments against the possibility of change, Aristotle attempted to set out a framework that would make change intelligible. Every change involves three essential ingredients: a pair of opposed characteristics or states (from which and to which, respectively, the change occurs) and a subject which underlies the change and persists through it. Schematically, every change, every case of "coming to be," can be described in this way: something, x, goes from being F to being not F, or vice versa. A musician comes to be because a man goes from being unmusical to being musical; a statue comes to be because some shapeless bronze takes on a definite form. Contrary to what P

armenides argued, coming to be does not involve getting something from nothing; it involves getting something which is F from something which is (among other things) not F.

These are the necessary preconditions for change. But what is change? Aristotle defines it in terms of his concepts of actuality and potentiality. Change, he tells us, is "the actuality of what is potentially, qua such" The process of building a house, for example, is the actuality of the buildable materials, qua buildable. The materials that are potentially a house are already actual even before the building begins - they are bricks and boards, etc. So the actuality with which Aristotle identifies change is that of the bricks and boards not qua bricks and boards, but qua buildable. It is precisely when the house is in the process of being built that this potentiality of the materials actually (and not merely potentially) exists as a potentiality. Once the process is completed, that potentiality has been replaced by a corresponding actuality, that of the completed house. The precise meaning of Aristotle’s definition of change is a subject of scholarly debate. For present purposes it is sufficient to note that in undergoing change a thing is actualizing a potentiality that it already has even before it changes. It is thus already part of its nature to be able to undergo change of that sort.

It is the job of a theoretical science to explain things, and that means that it must answer "Why?" questions. To answer such a question is to give a cause. Aristotle’s word is.‘explanation’ is an equally appropriate translation. But ‘cause’ is "said in many ways" In one sense, the cause of something is the material out of which it comes to be material cause. In another sense, it is the form or essence stated in the definition of the thing formal cause. In a third, it is the source of change or stability efficient cause. In a fourth, it is the end , what the thing is for. Note that it is not just events that have causes, in Aristotle’s view; houses and tigers have causes just as much as eclipses and explosions do. Note also that there can be more than one cause of the same thing e.g., bronze is the material cause of a statue, whereas a certain shape is its formal cause. Indeed, two things may be causes of one another, as exercise is the efficient cause of health, and health is the final cause of exercise.

A complete account of something will mention all of the causes that are appropriate to it. Artifacts clearly have causes in all four senses: a house is made of wood, by a builder, with a form and structure suitable to provide a shelter for human beings and their possessions. Mathematical objects, since they do not undergo change, have no efficient or final causes. Natural objects, such as plants and animals, clearly have the first three kinds of cause, for they come into being, are composed of matter (ultimately of the four elements), and have essential natures. But are there final causes in nature? Aristotle maintains, notoriously, that there are His teleological account of nature is central to his entire philosophical system.

His position here may strike us as an aberration if we identify final causes with conscious intentions. The final causes of artifacts are found in the minds of the artisans who made them; they are in that sense external to the artifacts themselves. (It is for this reason that artifacts do not count for Aristotle as genuine substances. Lacking final causes that are internal to them, they do not engage in activity of their own, and hence they have no essence, strictly speaking.) But final causes in nature are not like this at all. Rather, Aristotle’s idea is that the final causes of natural objects are internal to those objects. Consider the living creatures that populate the natural world. They behave in certain characteristic ways: they interact with their environment, nourish themselves, reproduce. Their being is defined by these functions and these characteristic activities. The parts of which they are composed enable them to fulfill these functions more or less successfully. It is not by accident that animals have teeth or eyes; these organs clearly have functions - they are for something. And what they are for is typically beneficial for the organism; they enable it to survive and to engage in the activities that define its being. It is function and activity, not purpose, that Aristotle claims to discern in nature.

This understanding of Aristotle’s teleology helps to explain why he believes that final, formal, and efficient causes often coincide . For just as the various parts and organs of an animal contribute toward its well-being and survival, the telos of the animal itself is to be a good (i.e., successful) specimen of its kind. So the final cause of a tiger is just to be a tiger, as specified in its formal cause (i.e., its definition). The coincidence of the efficient cause with the final and the formal can be seen most easily in the case of reproduction and development. The efficient cause of a tiger cub is a tiger (in Aristotle’s view, its father). As the cub grows, its process of development tends almost invariably (in the normal case - occasionally things go awry) toward the same outcome: a mature individual that, like its parents, satisfies the definition of a tiger.

The being of a living thing is thus inextricably bound up in its being alive and living the life that a thing of its kind lives. What is it that differentiates the living from the nonliving? Aristotle’s answer is: the presence of the soul We notice immediately an important difference between this and later conceptions of soul:for Aristotle is linked with life in general, rather than with mind, thought, or personality in particular. All living things have souls. But there are different degrees or levels of soul, associated with different capacities or functions. At the most fundamental level is the nutritive soul, the kind of soul common to all living things; for all plants and animals have the capacity to take in nourishment. Higher levels of soul account for the appetitive, locomotive, and perceptive capacities of humans and other animals. At the highest level is the rational soul, peculiar to humans.

But what is the soul? Aristotle defines it to be the form of the body. More precisely, it is the "first actuality of a natural body that has life potentially" The term ‘first actuality’ needs some explanation. As Aristotle uses the expression, a first actuality is not itself an activity or bit of behavior but a capacity or ability to act or to behave. It is thus a kind of potentiality an organizing principle that enables a living thing to go about the business of living. To have a soul, then, is to have the capacity to engage in certain characteristic activities. In the most general case, it is the capacity to metabolize. For higher levels of soul, it is the capacity to move about, to have desires and to fulfill them, to perceive, to contemplate.

The soul is therefore neither a material part of an animal, nor some immaterial thing capable of existing in separation from the body. For the soul is a set of capacities that a living thing has, and these capacities are incapable of existing on their own - they are the capacities of a living thing. Aristotle thus resists both a materialistic conception of the soul as some kind of bodily part and a Platonic conception which holds the soul to be independent of and, indeed, impeded by the body.

Much of Aristotle’s discussion of the soul concerns the topic of sense-perception .He discusses the physiology of each of the five senses in detail and defines perception in general as the reception in the soul of the perceptible form of an external object. His account of thought to some extent mirrors what he says about perception. In thinking the mind takes on the intelligible form of its object and in so doing becomes, in a sense, identical to it. Aristotle thereby avoids the problem of having somehow to relate a mental representation to an object external to the mind. But thought differs from perception in an important respect: whereas there are sense organs, there is, for Aristotle, no organ of thought . For this reason he holds that thought, unlike other psychic functions, is somehow separable from the body. It is not clear how well this aspect of Aristotle’s theory can be made to harmonize with his otherwise hylomorphic conception of the soul.

Thus far we have looked at some of Aristotle’s answers to the questions of the theoretical sciences. As we shall see, his approach to the practical sciences builds on those answers. The central question of ethics is how to live, i.e., what the good life is, and Aristotle’s answer is basically naturalistic. He takes it to be uncontroversial that all of our actions are aimed at some good. So the good, he reasons, is "that at which all things aim" And what is this good? It must be something that is chosen for its own sake, and not for the sake of something else. Aristotle’s answer is that it is happiness (eudaimonia) in the sense of well-being or flourishing. (It would be a mistake to think of happiness here in the narrow sense of a kind of mental or emotional state.) The well-being of a thing consists in its fulfilling its basic functions and performing its characteristic activities. Human happiness or well-being, then, consists in fulfilling the functions and performing the activities that define life for human beings. All animals nourish themselves, and grow, and perceive. What is distinctively human is the rational faculty, and that is what determines our well-being. Eudaimonia is therefore an "activity of soul in accordance with virtue or excellence . We flourish, then, when we do well the things that are distinctively human.

The remainder of Aristotle’s Ethics consists of an unpacking of this basic conception of eudaimonia. He distinguishes virtues of character from intellectual virtues, and discusses all of them in detail (Nicomachean Ethics II-VI). Intellectual virtues are excellences of the rational element in the soul. But the irrational element also has an aspect that is rational in that it is capable of being persuaded by reason, and the excellences of this part of the soul are virtues of character, or moral virtues (Nicomachean Ethics I.13). Such a virtue is a disposition to choose actions that are intermediate between the extremes of excess and deficiency. (For example, courage is a mean between cowardice and rashness.) These choices must be made in accordance with reason, as would be determined by a person of practical wisdom. So possession of the moral virtues implies the possession of the intellectual virtues, as well, since practical wisdom is an intellectual virtue. Of the intellectual virtues, the highest is that of theoretical contemplation. This, finally, is the activity of the soul with which Aristotle identifies the highest form of eudaimonia.

In Aristotle’s view, politics is continuous with ethics. For just as it is part of human nature to seek happiness, it is also part of human nature to live in communities. We are, Aristotle asserts, social animals (Politics I.2). The state is the highest form of community; it is a natural entity, and does not exist merely by convention. (The kind of state Aristotle has in mind is the relatively small city-state of fourth century Greece.) Plato had argued that the structure of the soul was like that of the state, with different psychic functions corresponding to different classes of citizens. For Aristotle, the analogy works the other way around. The state has a proper function and a nature in the same way that an individual organism does. Hence, to say what a state is we must determine what its proper function is.

Aristotle believes that a state exists for the sake of the good or happy life, so that the best form of government will be one which promotes the well-being of all of its citizens; and he goes on, after considering a variety of alternatives, to describe such a state in considerable detail (Politics VII). In his emphasis on the rule of law and the role of a constitution in defining a state, Aristotle’s ideas are still timely today. There are other aspects of his thought, however, such as his belief that there are natural rulers and natural slaves, that the contemporary reader will no doubt find repugnant.

Contributions In Different Fields

Science Education:

Has shown a renewed interest in Aristotle’s works. Today, theories in science are often based on abstract and mathematical models of the world. Students sometimes use the theories and equations without understanding how they were developed, their limitations, or even what problems they address. The development of an idea from Aristotle to the present would make physics more interesting and understandable. Aristotle’s works are reconstructions from fragmentary notes. He had the most rudimentary of scientific equipment, his measurements were not quantitative; and he considered only things that were observable with the eye. Ignoring these limitations has caused some to distort the significance of his work, sometimes to the point of considering Aristotle an impediment to the advancement of science. However, we should not project the framework of contemporary science on Aristotle’s work – but we should read his works and examine his Natural Philosophy in the context of his times.


In his work, Aristotle examined the nature of matter, space, time, and motion. He had few tools for experimentation and could not measure time or speeds. He would not allow invisible forces so his reasoning did not include gravity. Things fell to Earth and the moon circled the Earth because that was their nature. He proved that infinite linear motion and voids could not exist on Earth. Without those, he could not escape the complexities of the real world or fully understand inertia. In spite of his limitations, Aristotle made some remarkable contributions to physics and laid the groundwork for Galileo, Newton, and Einstein. He reasoned that infinite velocities could not exist, that time and movement are continuous and inseparable, and that time was even flowing, infinite, and the same everywhere at once. These are all true and a part of Einstein’s Theory of Relativity. Some consider that Aristotle’s greatest contribution to physics was his description of time.

Reading Aristotle reminds one of reading Einstein. He takes the simplest of observations and in it discovers fundamental truths. Force is a push or a pull. A horse can pull a cart and the cart pulls back on the horse and when the horse stops, the cart stops. Rest, then is the natural state of matter and the mover is acted on by that which it moves. These ideas became part of Newton’s Laws. He observed that there was both static and kinetic friction that opposed motion by studying shiphaulers. A hundred men could pull a ship but one man could not. Furthermore, he observed that the power needed to keep the ship moving depended on the force required and the speed. That is like the definition of power used today and, incidentally, something that Newton got wrong. Aristotle examined objects falling in fluids and realized friction existed there also. He found that the speed of objects increased as the weight of the object and decreased with the thickness of the fluid. This is now a part of Stoke’s Law for an object falling at its terminal velocity. He also considered what would happen if the fluid became thinner and thinner but rejected the conclusion as that would lead to a vacuum and an infinite speed, both which he considered impossibilities. Galileo allowed those impossibilities and is credited with discovering kinematics.


We sometimes forget that Aristotle proved the Earth was a sphere. He observed that the shadow of the Earth on the moon during an eclipse was an arc. That was not conclusive as a disk might give the same shadow. The phases of the Moon and its appearance during eclipses show it to be a sphere and the Earth might be also. As one walks toward the horizon, the horizon falls away; and, as one walks North or South, different stars appear. These are as if one is looking out from a sphere. All things made of Earth fall to Earth in such a way as to be as near the Earth as possible. A sphere is the shape that allows this as it is the shape with the smallest surface for a given volume. All things considered, the Earth must be a sphere. Interestingly, an extension of that last argument is used today to explain the erosion of mountains, surface tension, the shape of droplets, and why the moons, planets, and stars are spheres.

Aristotle concluded that since all things fall toward the center of the Earth or move round the Earth, that the Earth must be the center of the Universe. The Moon and planets move around the Earth in circular orbits but must move in circles within circles to explain the variance observed in their orbits. The stars are fixed spheres that rotate around the Earth and the Universe must be finite else the stars at the outer edge would have to move at infinite speed. Aristotle was aware that if the heavenly bodies were made of matter, that they would fly off like a rock from a sling. He therefore added to the elements a fifth element, aether, to compose the heavenly bodies. Aether could not be observed on Earth but objects composed of it could move forever in circles without friction or flying away. Perhaps Aristotle should have stopped with the moon, but the planets and stars were there and needed explaining. In spite of his model’s imperfections, Aristotle gave us a universe whose laws are invariant and capable of being discovered by observation and understood by reason. Aristotle’s model of the Universe lasted almost 20 centuries without significant modification and was so compelling that Renaissance philosophers and theologians built it into church doctrine.

Scientific Revolution:

However, Aristotle’s model did not fit well with new observations made by 15th century scientists. Copernicus realized that the planetary motions would be simpler and better explained if the Sun were the center of the universe. Tycho Brahe’s careful observations of planetary motions supported the Copernican model. Galileo used the first telescope to observe that Jupiter had moons that revolved around Jupiter and not the Earth. This was convincing evidence and Galileo championed a revision of Aristotle’s model. There was much resistance to the acceptance of the heliocentric model and Galileo was threatened with a charge of heresy for promoting the idea. Some people now consider Aristotle’s ideas as an impediment to the advancement of science. However, the impediment was not Aristotle’s ideas – but that Aristotle’s model of the universe had become woven into the doctrine of the Church.

Galileo’s kinematics was also in conflict with Aristotle’s work. Galileo’s experiment with falling bodies is considered as one of the ten greatest experiments of all time. He showed that a small weight fell from the Tower of Pisa at the same rate as one ten times as heavy. This was considered by some to be a triumph of Galileo’s kinematics over the simple empiricism of Aristotle. That was not, however, the whole story. Aristotle had not only examined objects falling in air but also in liquids. He found that the rate of fall in liquids increased as the weight of the object and decreased with the thickness of the fluid. This idea is consistent with Stoke’s Law for an object falling at its terminal velocity in fluids. Aristotle even had considered the case of a fluid with no thickness (a vacuum), but rejected the possibility since the speed would become infinite. However, Galileo’s experiment was performed in air and, while correct in a vacuum, Galileo’s mechanics were not exactly correct in air. Had Galileo dropped his objects from a much greater height, he would have found that the heavy object would reach the ground half again as fast as the small object. This is observable in hailstones where a large stone will strike the ground at almost twice the speed of a small stone. Galileo’s mechanics are only valid in a vacuum and even then would allow the velocity to eventually become infinite, which conflicts with Einstein’s relativity. No one has thought to criticize Galileo for that.


To the modern reader, Aristotle's views on astronomy, as presented in Metaphysics, Physics, De Caelo (On the Heavens) and Simplicius' Commentary, will most likely seem very bizarre, as they are based more on a priori philosophical speculation than empirical observation. Although Aristotle acknowledged the importance of "scientific" astronomy - the study of the positions, distances and motions of the stars - he nevertheless treated astronomy in the abstract, linking it to his overall philosophical world picture. As a result, the modern distinction between physics and metaphysics is not present in Aristotle, and in order to fully appreciate him we must try to abandon this pre-conception.

Aristotle argued that the universe is spherical and finite. Spherical, because that is the most perfect shape; finite, because it has a center, viz. the center of the earth, and a body with a center cannot be infinite. He believed that the earth, too, is a sphere. It is relatively small compared to the stars, and in contrast to the celestial bodies, always at rest. For one of his proofs of this latter point, he referred to an empirically testable fact: if the earth were in motion, an observer on it would see the fixed stars as moving, just as he now observes the planets as moving, that is from a stationary earth. However, since this is not the case, the earth must be at rest. To prove that the earth is a sphere, he produced the argument that all earthly substances move towards the center, and thus would eventually have to form a sphere. He also used evidence based on observation. If the earth were not spherical, lunar eclipses would not show segments with a curved outline. Furthermore, when one travels northward or southward, one does not see the same stars at night, nor do they occupy the same positions in the sky. That the celestial bodies must also be spherical in shape, can be determined by observation. In the case of the stars, Aristotle argued that they would have to be spherical, as this shape, which is the most perfect, allows them to retain their positions.

Scientific Progress:

Many thought, and still think, that Galileo’s work was the final overthrow of Aristotelian physics and the start of a revolution allowing science to advance. That is not the case. It is just the normal progress of science that models and theories are revised as better observations and understanding occur. The Revolution was not so much an overthrow of Aristotelian Physics as it was in moving from the observable to the imaginable – and in again separating science from theology and philosophy. It is ironic that Galileo was accused of heresy for questioning the theories of a man who thought everything should be open to question and reason.


Philosophy: A full presentation of the philosophical thought of Aristotle would require many volumes. However, some of the important points of that thought which influence the Aristotelian educational theory can be summarized briefly. Those points are:


Reality. The universe is composed of two ultimate entities, spirit or form and materiality or matter. All things are reducible to one or other of these basic entities.

Teleology. There is purpose, order and intelligence in the universe, stemming from the first being, the unmoved Mover, God.

The Nature of Man. Man is a rational animal. He is animal in his possession of a body With its physical needs and appetites. He is rational because he has a soul. The active element of the soul is part of the universal principle of life. This element is immortal. The passive element of the soul is the individual personality, with memories and thoughts relating to the experiences of life. This passive element ceases to exist with death. The soul and body form a necessary whole for the existence of the organism. The implications of this theory are:

Destiny. Man has no eternal destiny. He ceases to exist as an individual personality at death.

Nature. The highest faculty in man is his spiritual nature. Man acts according to his nature when he subordinates his physical appetites to reason.


Source of Truth. The faculty of reason in every man can be trained, through the principles of logic, to reason toward true conclusions.

Nature of Truth. Truth is objective. For example, a true proposition does not depend upon the mind of the individual man for its existence. Truths exist in nature and are discoverable by the reason of man.


Happiness. The highest good to which man may aspire is happiness. A truly happy life can be assessed only upon its completion.

Naturalism. A man lives happily when his actions are in accordance with his nature. Man's spiritual nature is superior to his physical nature. The highest good for any man is the activity of his soul.

Reason. The faculty of reason, resident in the soul of man, must guide his every action. The physical appetites must be controlled by reason. Reason, therefore, is the source of virtue.

Virtue. Man uses his reason to judge between the extremes of any given act. The middle course constitutes virtue. For example, the mean between the two extremes of the vice of rashness (excess of courage) and the vice of cowardice (lack of courage) is the virtue of temperate courage.


Purpose. The purpose of the state is to produce human good.

Naturalism. Man is social by nature. He will naturally be political. The difficulty in political philosophy is to determine how man may act reasonably and virtuously to achieve the best political action.

Reason. The ideal state must be reasoned as a mean between two governmental extremes.

Constitutional Monarchy. The best form of government is a constitutional monarchy, which is the mean between the extremes of despotism and democracy. The constitution guarantees moderation between the demands of the wealthy and the interests of the poor.

Public Education. The state is perpetuated through the education of its citizens. Therefore education is, of necessity, public in nature.

Aristotle’s Logic:

There are some areas in which Aristotle's influence is often called into question. In biology, where he made some of his greatest contributions, he was ultimately superseded and is now read only for historical reasons. In politics his ideas continue to be debated, but, still, even they are most useful in a historical context. Thus one might argue that his greatest contribution to Western thought was the creation of logic. That a single mind could essentially invent such a vast field might be difficult to grasp, but Aristotle almost single-handedly reinvented other fields as well, whether or not they fall into the category of areas in which he has been superseded.

Aristotle placed all learning into three categories–theoretical, practical, and productive–and logic did not fall into any of these. Rather, Aristotle saw logic as a tool that underlay knowledge of all kinds, and he undertook its study because he believed it to be a necessary first step for learning. Logic enables one to recognize when a judgment requires proof and to verify the validity of such proof. Two preliminary works provided the foundation for Aristotle's work in logic: Categories and On Interpretation. In the former, he defined and analyzed the following list of categories (each followed by an example):

Substance: man

Quantity: two cubits long

Quality: white

Relation: double

Place: in the Lyceum

Date: yesterday

Posture: is sitting

Possession: is wearing shoes

Action: cuts

Passivity: is cut

This list does not attempt to be exhaustive, and Aristotle himself did not always use it consistently. The purpose of these categories is to show how these predicates (categoria means predicate) can describe a subject. This foundational work therefore sets the boundaries for terms and the types of distinctions that are possible.

In On Interpretation Aristotle turns from terms to propositions, which are sentences that contain either truth or falsity. Propositions assert judgments about concepts; for Aristotle, concepts are the likenesses of things, as experienced by a given person, in contrast to objective reality. A proposition attempts to combine or separate concepts, and it is to be considered true when its combination or separation corresponds to a combination or separation of the things it represents. This recognition of language as a signifier therefore provides the basis for an understanding of what truth and falsity mean.

With Prior Analytics Aristotle made his most important contribution to logic: the syllogism. A syllogism consists of certain assumptions or premises from which a conclusion can be deduced. Aristotle referred to the terms as the "extremes" and the "middle." The middle term is the conclusion that links the two extremes. A traditional example runs as follows:

All men are mortal.

All Athenians are men.

Therefore all Athenians are mortal.

Aristotle goes on to characterize the possible forms of the syllogism and the conclusions it can generate. For example, each extreme, what we'd call a premise, must be affirmative or negative and have a scope, either universal or particular.

In Posterior Analytics, Aristotle attempted to show how his logical theory could apply to scientific knowledge. He argues that a science must be based on axioms (self-evident truths), from which one can draw definitions and hypotheses. Euclidean geometry provides an example of a system built on this kind of logical model. One starts with a small number of axioms and extrapolates from them various hypotheses or postulates.

Aristotle's contribution to logic has also been undervalued, for the syllogism makes up only a small part of modern studies. Philosopher and mathematician Bertrand Russell dismissed nearly all of Aristotle's points as false, excepting only the syllogism, which he deemed unimportant. Aristotle's thought had clear limitations, but his accomplishments are usually acknowledged with more admiration, regardless of their direct relevance today. His contribution to logic is thus generally considered to be his greatest achievement.

Analytics and the Organon

The Organon is the standard collection of Aristotle's six works on logic. The name Organon was given by Aristotle's followers, the Peripatetics.What we today call Aristotelian logic, Aristotle himself would have labeled "analytics". The term "logic" he reserved to mean dialectics. Most of Aristotle's work is probably not in its original form, since it was most likely edited by students and later lecturers. The logical works of Aristotle were compiled into six books in about the early 1st century AD:


On Interpretation

Prior Analytics

Posterior Analytics


On Sophistical Refutations

The order of the books 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 dialectics 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. There is one volume of Aristotle's concerning logic not found in the Organon, namely the fourth book of Metaphysics.

Aristotle’s Achievmentsarr.jpg

Aristotle’s greatest achievement is generally supposed to have been his Laws of Thought - part of his attempt to put everyday language on a logical footing. Like many contemporary philosophers he regarded logic as providing the key to philosophical progress. The traditional ‘laws of thought’ are that:

• whatever is, is (the law of identity);

• nothing can both be and not be (the law of non-contradiction); and

• everything must either be or not be (the law of excluded middle).

His Prior Analytics is the first attempt to create a system of formal deductive logic.

Aristotle is said to have written 150 philosophical treatises. The 30 that survive touch on an enormous range of philosophical problems, from biology and physics to morals to aesthetics to politics. Many, however, are thought to be "lecture notes" instead of complete, polished treatises, and a few may not be the work of Aristotle but of members of his school.

A full description of Aristotle's contributons to science and philosophy is beyond the scope of this exhibit, but a brief summary can be made: Whereas Aristotle's teacher Plato had located ultimate reality in Ideas or eternal forms, knowable only through reflection and reason, Aristotle saw ultimate reality in physical objects, knowable through experience. Objects, including organisms, were composed of a potential, their matter, and of a reality, their form; thus, a block of marble -- matter -- has the potential to assume whatever form a sculptor gives it, and a seed or embryo has the potential to grow into a living plant or animal form. In living creatures, the form was identified with the soul; plants had the lowest kinds of souls, animals had higher souls which could feel, and humans alone had rational, reasoning souls. In turn, animals could be classified by their way of life, their actions, or, most importantly, by their parts.

Though Aristotle's work in zoology was not without errors, it was the grandest biological synthesis of the time, and remained the ultimate authority for many centuries after his death. His observations on the anatomy of octopus, cuttlefish, crustaceans, and many other marine invertebrates are remarkably accurate, and could only have been made from first-hand experience with dissection. Aristotle described the embryological development of a chick; he distinguished whales and dolphins from fish; he described the chambered stomachs of ruminants and the social organization of bees; he noticed that some sharks give birth to live young -- his books on animals are filled with such observations, some of which were not confirmed until many centuries later.

Aristotle's classification of animals grouped together animals with similar characters into genera used in a much broader sense than present-day biologists use the term and then distinguished the species within the genera. He divided the animals into two types: those with blood, and those without blood or at least without red blood. These distinctions correspond closely to our distinction between vertebrates and invertebrates. The blooded animals, corresponding to the vertebrates, included five genera: viviparous quadrupeds mammals, birds, oviparous quadrupeds reptiles and amphibians, fishes, and whales which Aristotle did not realize were mammals. The bloodless animals were classified as cephalopods such as the octopus; crustaceans; insects which included the spiders, scorpions, and centipedes, in addition to what we now define as insects; shelled animals (such as most molluscs and echinoderms; and "zoophytes," or "plant-animals," which supposedly resembled plants in their form -- such as most cnidarians.

Aristotle's thoughts on earth sciences can be found in his treatise Meteorology -- the word today means the study of weather, but Aristotle used the word in a much broader sense, covering, as he put it, "all the affections we may call common to air and water, and the kinds and parts of the earth and the affections of its parts." Here he discusses the nature of the earth and the oceans. He worked out the hydrologic cycle: "Now the sun, moving as it does, sets up processes of change and becoming and decay, and by its agency the finest and sweetest water is every day carried up and is dissolved into vapour and rises to the upper region, where it is condensed again by the cold and so returns to the earth." He discusses winds, earthquakes (which he thought were caused by underground winds), thunder, lightning, rainbows, and meteors, comets, and the Milky Way (which he thought were atmospheric phenomena). His model of Earth history contains some remarkably modern-sounding ideas:

The same parts of the earth are not always moist or dry, but they change according as rivers come into existence and dry up. And so the relation of land to sea changes too and a place does not always remain land or sea throughout all time, but where there was dry land there comes to be sea, and where there is now sea, there one day comes to be dry land. But we must suppose these changes to follow some order and cycle. The principle and cause of these changes is that the interior of the earth grows and decays, like the bodies of plants and animals. . . .

But the whole vital process of the earth takes place so gradually and in periods of time which are so immense compared with the length of our life, that these changes are not observed, and before their course can be recorded from beginning to end whole nations perish and are destroyed.

Where Aristotle differed most sharply from medieval and modern thinkers was in his belief that the universe had never had a beginning and would never end; it was eternal. Change, to Aristotle, was cyclical: water, for instance, might evaporate from the sea and rain down again, and rivers might come into existence and then perish, but overall conditions would never change.

In the later Middle Ages, Aristotle's work was rediscovered and enthusiastically adopted by medieval scholars. His followers called him Ille Philosophus (The Philosopher), or "the master of them that know," and many accepted every word of his writings -- or at least every word that did not contradict the Bible -- as eternal truth. Fused and reconciled with Christian doctrine into a philosophical system known as Scholasticism, Aristotelian philosophy became the official philosophy of the Roman Catholic Church. As a result, some scientific discoveries in the Middle Ages and Renaissance were criticized simply because they were not found in Aristotle. It is one of the ironies of the history of science that Aristotle's writings, which in many cases were based on first-hand observation, were used to impede observational science.

To summarize: Aristotle’s philosophy laid out an approach to the investigation of all natural phenomena, to determine form by detailed, systematic work, and thus arrive at final causes. His logical method of argument gave a framework for putting knowledge together, and deducing new results. He created what amounted to a fully-fledged professional scientific enterprise, on a scale comparable to a modern university science department. It must be admitted that some of his work - unfortunately, some of the physics - was not up to his usual high standards. He evidently found falling stones a lot less interesting than living creatures. Yet the sheer scale of his enterprise, unmatched in antiquity and for centuries to come, gave an authority to all his writings.

It is perhaps worth reiterating the difference between Plato and Aristotle, who agreed with each other that the world is the product of rational design, that the philosopher investigates the form and the universal, and that the only true knowledge is that which is irrefutable. The essential difference between them was that Plato felt mathematical reasoning could arrive at the truth with little outside help, but Aristotle believed detailed empirical investigations of nature were essential if progress was to be made in understanding the natural world.

Aristotle’s Methods

Scientific Method:

In ancient times, events in Nature had been explained as the actions of the gods. The early Greek philosophers questioned the role of the gods as the cause of events and by the fifth century B.C. the Greek philosophers, such as Socrates, had separated philosophy from theology. But, if the gods were not the cause of events, what was? Philosophers advanced explanations based on philosophical principles and mathematical forms. Aristotle found that unsatisfactory. He decided the principles of nature could be found within nature and could be discovered using careful observation and inductive reasoning. Observations must be capable of being observed by the senses and should include the four causes: the composition, the shape or form, the motion (or change), and the end result (or purpose). Identifying the four causes insured a thorough understanding of the event. Chance or spontaneity were not considered causes. He thought all things in Nature should be open to examination and subject to reason – and he set about applying his methods to all knowledge.

Aristotle founded a school in Athens at the Lyceum which provided the world’s first comprehensive study of human knowledge from the perspective of natural philosophy. His lectures followed a pattern that formed the basis of the scientific method. They included a statement of the idea or problem, the precise definition of terms, a statement of what he and other scholars thought about the matter, the observations, arguments based on how well the ideas agreed with observation, and finally what could be concluded. His lectures notes are important as they not only show clearly his reasoning but they preserve many of the ideas of his contemporaries.


His work, The Rhetoric, is widely regarded as one of the most important pieces of writing on the subject of persuasion ever published in Western culture.

Aristotle addressed the question: how do we come to believe things before we've confirmed "the truth" for ourselves?

Aristotle details three major modes of proof --ETHOS, PATHOS, and LOGOS. Think of them as three ways by which people are persuaded to believe things and/or act in certain ways.

ETHOS-- "ethical," credibility appeal.

Sometimes we come to believe something or to act upon something simply because someone we trusted told us it was so. Aristotle suggests that the source of the material--the perception of the person the persuasive appeal comes from--is the most powerful mode of persuasion.

For most children, parents/caretakers are probably the first and most credible sources of information. This is why so many of us believed that Santa Claus magically flies the air in a sleigh pulled by reindeer. It isn't the most logical story, but it came from people we trusted and was also very nice to imagine and believe.

Other examples of ETHOS are:

Doctors we trust for medical advice

Newspapers/news stations/news anchors we turn to for accurate information

Brands/companies whose products we feel are safe, trustworthy, or of high quality

Celebrity endorsers who appear in commercials to sell products

PATHOS--"pathetic," emotional appeal.

Sometimes we come to believe something or to act upon something simply because of a gut feeling or an appeal to our emotions. We act out of fear and greed and also out of love and compassion. We even act in certain ways because we are concerned about what others will think of us. Pathos is about emotion and how it moves us to do things and make decisions.

LOGOS--"logical," rational appeal.

Sometimes we come to believe something or to act upon something simply because someone gave us what we considered to be a "good reason." This is where evidence and reasoning become parts of the persuasive process. Logos is the most complicated of the modes of proof. Unlike ethos and pathos, logos allows us to use the same tool logic) that the "persuader" is using, which in turn allows us to examine he topic at hand with a critical eye.Use of support material constitutes offering "good reasons" to accept a claim.


Return to the course of Education. The importance of education in the philosophy of Aristotle was great, since the individual man could learn to use his reason to arrive at virtue, happiness, and political harmony only through the process of education.

1. AIM OF EDUCATION. The purpose of education is to produce a good man. Man is not good by nature. He must learn to control his animal activities through the use of reason. Only when man behaves by habit and reason, according to his nature as a rational being, is he capable of happiness. Education must aim at the development of the full potentialities of each man. It must seek the development of man's intellectual capacities to their fullest extent. It must aim also at developing each individual's body to its highest level of health and strength.

2. EDUCATION OF WOMEN. Women were considered inferior to men. The nature of women suggested that their proper function was fulfilled exclusively in the home. Women would not be educated with men. They would receive training in gymnastics and domestic arts to enable them to manage households, to bear and raise children, and to please and be obedient to their husbands.

3. EDUCATION OF MEN. Since citizenship would extend only to the aristocracy, which included rulers, soldiers, and priests, education would be given exclusively to this group. The farmer, laborer, merchant, and slave would be trained in whatever specific skills were required of them. Training in industrial arts or vocational skills is not education. Education is that which liberates man, enabling him to live his leisured existence according to his full potentialities. Education is therefore a practical means to the end of achieving the acme of man's nature.

4. THE CONTENT OF EDUCATION. Education must not serve any mean or vocational activity. These activities are the functions of slaves. The subject material must train the future rulers in the use of reason. Future rulers must learn obedience and responsibility before they rule. We may infer from the curriculum of the Academy that the following subjects would be taught:

Basics. These would include reading, writing and mathematics (not for purposes of trade, but as a preparation for the intellectual abstractions of higher mathematics).

Natural Sciences. Aristotle emphasized the natural sciences of astronomy, biology, physiology, zoology, chemistry and physics.

Physical Education. The training of the body is important to the physical well-being of every citizen.

Humanities. Rhetoric, grammar, poetry, politics and philosophy would be important subjects. During the early education of the child, Aristotle would have the state legislature censor the material which would be read by children.

THE METHOD OF EDUCATION. Aristotle placed habit high in the learning process. Man learns by nature, by habit, and by reason. Consequently, the teacher would organize materials according to the laws of reason. Repetitive drill would be used to reinforce what was understood by elementary knowledge of reading and writing. Arithmetic was never developed to a sophisticated extent because of the awkward method of writing numerals.


Education must not serve any mean or vocational activity. These activities are the functions of slaves. The subject material must train the future rulers in the use of reason. Future rulers must learn obedience and responsibility before they rule. We may infer from the curriculum of the Academy that the following subjects would be taught:

Basics. These would include reading, writing and mathematics (not for purposes of trade, but as a preparation for the intellectual abstractions of higher mathematics).

Natural Sciences. Aristotle emphasized the natural sciences of astronomy, biology, physiology, zoology, chemistry and physics.

Physical Education. The training of the body is important to the physical well-being of every citizen.

Humanities. Rhetoric, grammar, poetry, politics and philosophy would be important subjects. During the early education of the child, Aristotle would have the state legislature censor the material which would be read by children.