Aristotle

(384-322 BC)
Listen to Richard Sorabji explain why Aristotele is the greatest philosopher. Audio thanks to BBC radio.
Home: Stagira, in Macedonia 
School: Lyceum, one of the first universities/ the Peripatetic ("strolling" school)
Influences: Socrates, Plato, he probably was influenced by his own famous student, Alexander the Great
Rational/Empirical: First true Empiricist/Rationalist Synthesis, the foundation of science. 
"There is nothing in the intellect that was not first in the senses"
Aristotle's Key discovery: He agreed with the concept of forms or essences, but he felt they could only be understood by studying nature, empirically, when enough manifestations were observed. The object of rational thought must be an empirical object - as he himself said: "The body is not a hindrance" -a concept running counter to Plato and Pythagoras. This also represented the beginnings of physiological psychology.
Influence: With Socrates, and Plato, the most famous of Greek Philosophers. Rediscovery of Aristotle (by Arab philosopher Arreos) led to rebirth of science. His work helped to shape modern language and common sense. Logos, Ethos and pathos still are the tools of persuasive speech.
Proposed construct: Forms and Teleology. All things had an entelechy, or purpose inherent in their structure.
Greatest achievement(s): Foundation of the Scientific method (Categorization). Laws of Association - Law of contiguity, frequency, similarity/contrast. This seminal law would DOMINATE philosophy on the workings of the mind for eons. The mind was held to work by forming empirical sensations according to their connections in space and time, and their similarities and differences. The strength of memories would evolve from repetition. Dreams were held to be lingering sensory images, rather than portents of a spiritual nature. His theories would influence psychology and the workings of the mind profoundly - especially materialists.
Negatives: 1) The Gestalt-ist Lewin, would point out that science suffered from an overuse and over-dependence on Aristotle's categories. For example, the use of categorization in psychological pathologies would lead to a false belief that psychologically impaired people differed in kind and not just in degree, from healthy individuals - causing them to become ostracized. An understanding of phenomena on a continuum rather than separate categories would first be promulgated by Galileo, 1700 years later.
2) The tying of Aristotle's philos to Christian Dogma unfortunately continued other erroneous ideas of Aristotle's - i.e. such as the idea that heavenly bodies were fixed and perfect - or that some life came about through spontaneous generation.
Surviving works: Unlike Plato. Aristotle was a failed dialogist, and accordingly, his writings are of a more technical nature. His writings on the nature and properties of being, which Aristotle called First Philosophy, were given the title Metaphysics in the first published edition of his works (60? BC), because in that edition they followed Physics. His treatment of the Prime Mover, or first cause, as pure intellect, perfect, "the thought of thought," is given in the Metaphysics. (Definition of metaphysics: General, abstract theories of reality).
"All men by nature desire knowledge." 
"What is a friend?" "A single soul dwelling in two bodies." (This was meant literally)
Aristotle was born son of a physician to the royal court. At the age of 17, he went to Athens to study at Plato's Academy. He remained there for about 20 years, as a student and then as a teacher. Later, he would move to Macedonia and become a tutor to the young Alexander the Great. In 335, when Alexander became king, Aristotle returned to Athens and established his own school, the Lyceum. Because much of the discussion in his school took place while teachers and students were walking about the Lyceum grounds, Aristotle's school came to be known as the Peripatetic ("walking" or "strolling") school. 
"No great genius has ever existed without some touch of madness." Attributed by Seneca in Moral Essays, "De Tranquillitate Animi" (On Tranquility of Mind), sct. 17, subsct. 10. (See Creative Illness)
A certain degree of neurosis is of inestimable value as a drive, especially to a psychologist. Sigmund Freud.
At the academy, after a short but fruitless period of writing dialouge, Aristotle wrote some short technical notes, such as a dictionary of philosophic terms and a summary of the doctrines of Pythagoras. Nearly all of these early works are lost. Still extant, however, are Aristotle's lecture notes for carefully outlined courses treating almost every branch of knowledge and art. The texts on which Aristotle's reputation rests are largely based on these lecture notes, which were collected and arranged by later editors. 
"So it is naturally with the male and the female; the one is superior, the other inferior; the one governs, the other is governed; and the same rule must necessarily hold good with respect to all mankind." From politiks. 
Aristotle was an early proponent of earth as a globe.
Not so much a theory of the universe as a simple picture of the planet we call home, the flat-earth model proposed that Earth’s surface was level. Although everyday experience makes this seem a reasonable assumption, direct observation of nature shows the real world isn’t that simple. For instance, when a sailing ship heads into port, the first part that becomes visible is the crow’s-nest, followed by the sails, and then the bow of the ship. If the Earth were flat, the entire ship would come into view at once as soon as it came close enough to shore. The Greek philosopher Aristotle provided two more reasons why the Earth was round. First, he noted that Earth’s shadow always took a circular bite out of the moon during a lunar eclipse, which would only be possible with a spherical Earth. (If the Earth were a disk, its shadow would appear as an elongated ellipse at least during part of the eclipse.) Second, Aristotle knew that people who journeyed north saw the North Star ascend higher in the sky, while those heading south saw the North Star sink. On a flat Earth, the positions of the stars wouldn’t vary with a person’s location. Despite these arguments, which won over most of the world’s educated citizens, belief in a flat Earth persisted among many others. Not until explorers first circumnavigated the globe in the 16th century did those beliefs begin to die out. Yet a diehard core of flat-earth believers persisted even past the days of the Apollo Moon missions and those glorious images of a spherical Earth suspended against the blackness of space.
Among the texts are treatises on logic, called Organon ("instrument"), because they provide the means by which positive knowledge is to be attained. His works on natural science include Physics, which gives a vast amount of information on astronomy, meteorology, plants, and animals. To his son Nicomachus he dedicated his work on ethics, called the Nicomachean Ethics. Other essential works include his Rhetoric, his Poetics (which survives in incomplete form), and his Politics (also incomplete).
Methods:One of the most distinctive of Aristotle's philosophic contributions in these texts was a new notion of causality. Each thing or event, he thought, has more than one "reason" that helps to explain what, why, and where it is. Earlier Greek thinkers had tended to assume that only one sort of cause can be really explanatory; Aristotle proposed four. (Note: This is not strictly true. The word Aristotle uses, aition, "a responsible, explanatory factor" is not synonymous with the word cause in its modern sense.)
These four "causes" are the material cause, the matter out of which a thing is made; the efficient cause, the source of motion, generation, or change; the formal cause, which is the species, kind, or type; and the final cause, the goal, or full development, of an individual, or the intended function of a construction or invention. Thus, the material cause of a statue is the marble from which it was carved; the efficient cause is the sculptor; the formal cause is the shape the sculptor realized-Hermes, perhaps, or Aphrodite; and the final cause is its function, to be a work of fine art.
==These four causes ==
Material cause, the matter out of which a thing is made
Formal cause, which is the species, kind, or type
Efficient cause, the source of motion, generation, or change
Final cause, the goal, or full development person's entelechy.
In each context, Aristotle insists that something can be better understood when its causes can be stated in specific terms rather than in general terms. Thus, it is more informative to know that a sculptor made the statue than to know that an artist made it; and even more informative to know that Polycleitus chiseled it rather than simply that a sculptor did so.
Aristotle thought his causal pattern was the ideal key for organizing knowledge. His lecture notes present impressive evidence of the power of this scheme.
Unfortunately for us, this mindset became a lot more than an organizing scheme for class notes - it became the foundation of religious thought, and therefore, nearly all of thought for about two eons. And once it became a part of religiuos thought, the errors contained in this "thought process" became protected by dogma.
Aristotle writes of natural teleology:
"Whenever a sequence has an end, the earlier action and the next in order are done for the end… And since nature is of two sorts, as matter and as form, and the form is the end, and since everything else is for the end, the from must be the cause that the other things are for." 
(Physics, VIII 10-33)
This sort of reasoning is alien to scientific thought. There is no distinction between matter and form in science, at least as Aristotle conceived it. Rather, science is a purely materialistic study, with any form being the result of different combinations of matter. The idea of an eidos, or destined form, of natural processes is not compatible with scientific thinking, which looks at causes and effects from a strictly empirical point of view - in other words, we cannot assume that any process has a final cause "in mind". The sad truth is, that these wonderful certainties that Aristotle sought, and promulgated, are mere illusions.
Doctrines: Some of the principal aspects of Aristotle's thought can be seen in the following summary of his doctrines, or theories.
"Plato is dear to me, but dearer still is truth."
Perhaps because of the influence of his father's medical profession, Aristotle's philosophy laid its principal stress on biology, in contrast to Plato's emphasis on mathematics - (which Plato learned from Pythagoras). Instead, he proposed a Scala Naturae - A Hierarchy of life, based on a fixed (evolution is not possible) system of life, from vegetative souls, to sensitive (animals), to rational, all of which man alone possessed (He transcended and included lower levels). All life was driven towards perfection, the "Unmoved Mover", which resided at the top of the heirarchy. Each species reproduced true to type. An only exception occurs, Aristotle thought, when some "very low" worms and flies come from rotting fruit or manure by "spontaneous generation." While the species form a hierarchical scale from simple (worms and flies at the bottom) to complex (human beings at the top), evolution is not possible.
Aristotle was the first Comparative anatomist and through his observations he postulated that growth, purpose, and direction were built into nature. Although science studies general kinds, according to Aristotle, these kinds find their existence in particular individuals. Science and philosophy must therefore balance, not simply choose between, the claims of empiricism (observation and sense experience) and formalism (rational deduction). This claim planted the seeds of true science
For Aristotle, psychology was a study of the soul. He challenged the Pythagorean doctrine that the soul is a spiritual entity imprisoned in the body, presenting a synthesis of the earlier notion that the soul does not exist apart from the body and of the Platonic notion of a soul as a separate, nonphysical entity -Interactionism - emergentism. Through the functioning of the soul, the moral and intellectual aspects of humanity are developed. Aristotle argued that human insight in its highest form "active mind" is not reducible to a mechanical process. (Humanistic/Holist/Vitalist), although he postulated a "passive mind" and a common sense that existed to deal with biological functions and trivial maters that does not appear to transcend physical nature.Insisting that form (the essence, or unchanging characteristic element in an object) and matter (the common undifferentiated. characterless substratum of things) always exist together, Aristotle defined a soul as a "kind of functioning of a body organized so that it can support vital functions." Whether any part of the human soul is immortal, and, if so, whether its immortality is personal, are not entirely clear in his treatise On the Soul.
Through the functioning of the soul, the moral and intellectual aspects of humanity are developed. Aristotle argued that human insight in its highest form (nous poetikos, "active mind") is not reducible to a mechanical physical process a form of thought known as Vitalism. His insight, however, presupposes an individual "passive mind" that does not appear to transcend physical nature. Aristotle clearly stated the relationship between human insight and the senses in what has become a slogan of empiricism-the view that knowledge is grounded in sense experience. "There is nothing in the intellect," he wrote, "that was not first in the senses."
It seemed to Aristotle that the individual's freedom of choice made an absolutely accurate analysis of human affairs impossible. "Practical science," then, such as politics or ethics, was called science only by courtesy and analogy. The inherent limitations on practical science are made clear in Aristotle's concepts of human nature and self-realization. Human nature certainly involves, for everyone, a capacity for forming habits; but the habits that a particular individual forms depend on that individual's culture and repeated personal choices. All human beings want "happiness," defined as an active, engaged realization of their innate capacities, but this goal can be achieved in a multiplicity of ways. (Personal Observation: Yet, in any case, it requires self awareness.)
Aristotle's Nicomachean Ethics is an analysis of character and intelligence as they relate to happiness. Aristotle distinguished two kinds of "virtue," or human excellence: moral and intellectual. Moral virtue is an expression of character, formed by habits reflecting repeated choices. A moral virtue is always a mean between two less desirable extremes. Courage, for example, is a mean between cowardice and thoughtless rashness; generosity, between extravagance and parsimony. Intellectual virtues are not subject to this doctrine of the mean. Aristotle argued for an elitist ethics: Full excellence can be realized only by the mature male adult of the upper class, not by women, or children, or barbarians (non-Greeks), or salaried "mechanics" (manual workers) for whom, indeed, Aristotle did not want to allow voting rights.
In politics, many forms of human association can obviously be found; which one is suitable depends on circumstances, such as the natural resources, cultural traditions, industry, and literacy of each community. Aristotle did not regard politics as a study of ideal states in some abstract form, but rather as an examination of the way in which ideals, laws, customs, and property interrelate in actual cases. He thus approved the contemporary institution of slavery but tempered his acceptance by insisting that masters should not abuse their authority, since the interests of master and slave are the same. The Lyceum library contained a collection of 158 constitutions of the Greek and other states. Aristotle himself wrote the Constitution of Athens as part of the collection, and after being lost, this description was rediscovered in a papyrus copy in 1890. Historians have found the work of great value in reconstructing many phases of the history of Athens.
In Western thought, systematic logic is considered to have begun with Aristotle's collection of treatises, the Organon [tool]. Aristotle introduced the use of variables: While his contemporaries illustrated principles by the use of examples, Aristotle generalized, as in: All x are y; all y are z; therefore, all x are z. Aristotle posited three laws as basic to all valid thought: the law of identity, A is A; the law of contradiction, A cannot be both A and not A; and the law of the excluded middle, A must be either A or not A. Aristotle believed that any logical argument could be reduced to a standard form, known as a syllogism. A syllogism is a sequence of three propositions: two premises and the conclusion. By varying the form of the proposition and the modifiers (such as all, no, and some), a few specific forms may be delimited. Although Aristotle was concerned with problems in modal logic and other minor branches, it is usually agreed that his major contribution in the field of logic was his elaboration of syllogistic logic; indeed, the Aristotelian statement of logic held sway in the Western world for 2,000 years. Nonetheless, various logicians did, during that time, take issue with parts of Aristotle's thought. In logic, Aristotle developed rules for chains of reasoning that would, if followed, never lead from true premises to false conclusions (validity rules). In reasoning, the basic links are syllogisms: pairs of propositions that, taken together, give a new conclusion. For example, "All humans are mortal" and "All Greeks are humans" yield the valid conclusion "All Greeks are mortal." Science results from constructing more complex systems of reasoning. In his logic, Aristotle distinguished between dialectic and analytic. Dialectic, he held, only tests opinions for their logical consistency; analytic works deductively from principles resting on experience and precise observation. This is clearly an intended break with Plato's Academy, where dialectic was supposed to be the only proper method for science and philosophy alike. For more on logic, consult my Argumentation/Logic Section. 
In his metaphysics, Aristotle argued for the existence of a divine being, described as the Prime Mover  , who is responsible for the unity and purposefulness of nature. God is perfect and therefore the aspiration of all things in the world, because all things desire to share perfection. Other movers exist as well-the intelligent movers of the planets and stars (Aristotle suggested that the number of these is "either 55 or 47"). The Prime Mover, or God, described by Aristotle is not very suitable for religious purposes, as many later philosophers and theologians have observed. Aristotle limited his "theology," however, to what he believed science requires and can establish. Aristotle's prime mover was not even directly responsible or involved in human life, since it was incapable of comprehending inferior realms of thought. In fact, Aristotle guessed that the Prime Mover might even be unaware of humanity's existence. (I guess the prime mover didn't transcend and include...)
Epilogue: Aristotle's works were lost in the West after the decline of Rome. During the 9th century AD, Arab scholars introduced Aristotle, in Arabic translation, to the Islamic world (see ISLAM). The 12th-century Spanish-Arab philosopher Averroes is the best known of the Arabic scholars who studied and commented on Aristotle. In the 13th century, the Latin West renewed its interest in Aristotle's work, and Saint Thomas Aquinas found in it a philosophical foundation for Christian thought. Church officials at first questioned Aquinas's use of Aristotle; in the early stages of its rediscovery, Aristotle's philosophy was regarded with some suspicion, largely because his teachings were thought to lead to a materialistic view of the world. Nevertheless, the work of Aquinas was accepted, and the later philosophy of scholasticism continued the philosophical tradition based on Aquinas's adaptation of Aristotelian thought.
The influence of Aristotle's philosophy has been pervasive; it has even helped to shape modern language and common sense. His doctrine of the Prime Mover as final cause played an important role in theology. His views of mechanics and physics were the prevailing paradigms until Galileo and Newton overturned them. Until the Renaissance, and even later, astronomers and poets alike admired his concept of the universe. Zoology rested on Aristotle's work until British scientist Charles Darwin modified the doctrine of the "change-less-ness" of species in the 19th century. Until the 20th century, logic meant Aristotle's logic. In the 20th century a new appreciation has developed of Aristotle's method and its relevance to education, literary criticism, the analysis of human action, and political analysis.
Not only the discipline of zoology, but also the world of learning as a whole, seems to amply justify Darwin's remark that the intellectual heroes of his own time "we're mere schoolboys compared to old Aristotle."
syllogism, a mode of argument that forms the core of the body of Western logical thought. Aristotle defined syllogistic logic, and his formulations were thought to be the final word in logic; they underwent only minor revisions in the subsequent 2,200 years. Every syllogism is a sequence of three propositions such that the first two imply the third, the conclusion. There are three basic types of syllogism: hypothetical, disjunctive, and categorical. The hypothetical syllogism, modus ponens, has as its first premise a conditional hypothesis: If p then q; it continues: p, therefore q. The disjunctive syllogism, modus tollens, has as its first premise a statement of alternatives: Either p or q; it continues: not q, therefore p. The categorical syllogism comprises three categorical propositions, which must be statements of the form all x are y, no x is y, some x is y, or some x is not y. A categorical syllogism contains precisely three terms: the major term, which is the predicate of the conclusion; the minor term, the subject of the conclusion; and the middle term, which appears in both premises but not in the conclusion. Thus: All philosophers are men (middle term); all men are mortal; therefore, All philosophers (minor term) are mortal (major term). The premises containing the major and minor terms are named the major and minor premises, respectively. Aristotle noted five basic rules governing the validity of categorical syllogisms: The middle term must be distributed at least once (a term is said to be distributed when it refers to all members of the denoted class, as in all x are y and no x is y); a term distributed in the conclusion must be distributed in the premise in which it occurs; two negative premises imply no valid conclusion; if one premise is negative, then the conclusion must be negative; and two affirmatives imply an affirmative. John Venn, an English logician, in 1880 introduced a device for analyzing categorical syllogisms, known as the Venn diagram. Three overlapping circles are drawn to represent the classes denoted by the three terms. Universal propositions (all x are y, no x is y) are indicated by shading the sections of the circles representing the excluded classes. Particular propositions (some x is y, some x is not y) are indicated by placing some mark, usually an "X, in the section of the circle representing the class whose members are specified. The conclusion may then be read directly from the diagram.