History of philosophy
The
history of philosophy is the study of philosophical ideas and concepts through time. Issues specifically related to history of philosophy might include (but are not limited to): How can changes in philosophy be accounted for historically? What drives the development of thought in its historical context? To what degree can philosophical texts from prior historical eras even be understood today?
All cultures â€" be they
prehistoric,
ancient,
mediæval, or
modern;
Eastern,
Western,
religious or
secular â€" have had their own unique schools of philosophy, arrived at through both inheritance and through independent discovery. Such theories have grown from different
premises and approaches, examples of which include
rationalism (theories arrived at through
logic),
empiricism (theories arrived at through observation), and even through
leaps of faith, hope and inheritance (such as the
supernaturalist philosophies and
religions.
History of philosophy seeks to catalogue and classify such development, and therefore understand the development of philosophical ideas through time.
Western philosophy has a long history. Conventionally divided into four large eras - the Ancient, Medieval, Modern and Contemporary. The Ancient era runs through the fall of Rome and includes the Greek philosophers such as
Plato. The Medieval period runs until roughly the late
1400s and the
Renaissance. The "Modern" is a word with more varied use, which includes everything from
Post-Medieval through the specific period up to the
20th century. Contemporary philosophy encompasses the philosophical developments of the
20th century up to the present day.
Western Philosophy is generally said to begin in the Greek cities of western Asia Minor (Ionia) with
Thales of Miletus, who was active around 585 B.C. and left us the opaque dictum, "All is water." His most noted students were
Anaximenes of Miletus ("All is air") and
Anaximander.
Other thinkers and schools appeared throughout Greece over the next couple of centuries. Among the most important were
Heraclitus ("All is fire", all is
chaotic and transitory),
Anaxagoras (reality is so ordered that it must be in all respects governed by Mind), the
Pluralists and
Atomists (the world is composite of innumerable interacting parts), the
Eleatics Parmenides and
Zeno (All is One and change is impossible), the
Sophists (became known (perhaps unjustly) for claiming that truth was no more than opinion and for teaching people to argue fallaciously to prove whatever conclusions they wished). This whole movement gradually became more concentrated in
Athens, which had become the dominant city-state in
Greece.
There is considerable discussion about why
Athenian culture encouraged philosophy, but one popular theory says that it occurred because Athens had a direct
democracy. It is known from Plato's writings that many sophists maintained schools of debate, were respected members of society, and were well paid by their students. It is also well known that orators had a tremendous influence on Athenian history, possibly even causing its failure (See
Battle of Lade). One other theory for the popularity of philosophical debate in Athens was due to the use of slavery there - the workforce, mainly slaves, performed the labour that otherwise would have been taken up by the male population of the city. Freed from working in the fields or in productive activity, they were then free to engage in the assemblies of Athens and spend long hours discussing popular philosophical questions. The theory fills in the blanks by saying that the Sophists' students wanted to acquire the skills of oration in order to influence the
Athenian Assembly, and thereby grow wealthy and respected. Since winning debates led to wealth, the subjects and methods of debate became highly developed.
The key figure in transforming Greek philosophy into a unified and continuous project - the one still being pursued today - is
Socrates, who studied under several Sophists. He then spent much of his life engaging everyone in Athens in a discussion to try to determine whether anyone had a good idea of what they were talking about, especially when they talked about important matters like justice, beauty and truth. He wrote nothing, but inspired many disciples. He was executed in
399 BCE on the charge that philosophy and sophistry, interchangeably, was destroying the piety and moral fiber of the city.
 |
Raphael's The School of Athens (1509) with Plato and Aristotle in the centre. |
His most important student was
Plato, who founded the
Academy of Athens and wrote a number of philosophical dialogues using his master's methods of inquiry to examine problems. Central ideas are the
Theory of Forms, that the mind is imbued with an innate capacity to understand and apply concepts to the world, and that these concepts are in a significant way more real, or more basically real, than the things of the world around us; the immortality of the soul, and the idea that it too is more important than the body; the idea that evil is a kind of ignorance, that only knowledge can lead to virtue, that art should be subordinate to moral purposes, and that society should be ruled by a class of philosopher kings. In the later dialogues Socrates figures less prominently, and the Theory of Forms is cast in doubt; more directly ethical questions become the focus. Interestingly, in his most famous work,
The Republic, Plato attacks the system of democracy, blaming it for the defeat of Athens in the
Peloponnesian War - he attributes the indecision of the masses (who voted on everything, including military strategy) as the reason for military defeat. He proposed instead a three tiered structure of society, with workers, guardians and philosophers, in ascending order of importance (convenient for him and his disciples, clearly), citing the philosophers greater knowledge of the forms as the reason for them being more appropriate in running society.
Plato's most outstanding student was
Aristotle, perhaps the first truly systematic philosopher.
Aristotelian logic was the first type of
logic to attempt to categorize every valid
syllogism. A syllogism is a form of argument that is guaranteed to be accepted, because it is known (by all educated persons) to be
valid. A crucial assumption in
Aristotelian logic is that it has to be about real objects. Two of Aristotle's syllogisms are invalid to modern eyes. For example, "All A are B. All A are C. Therefore, some B are C." This syllogism fails if set A is empty.
Medieval philosophy was greatly concerned with the nature of God, and the application of
Aristotle's
logic and thought to every area of life.
If God exists at all, surely He is the most important feature of the universe, and therefore worthy of study. One continuing interest in this time was to prove the existence of God, through logic alone, if possible.
One early effort was the
cosmological argument, conventionally attributed to
Thomas Aquinas. The argument roughly is that everything that exists has a cause. Therefore, there must be an uncaused first cause, and this is God. Aquinas also adapted this argument to prove the goodness of God. Everything has some goodness, and the cause of each thing is better than the thing caused. Therefore, the first cause is the best possible thing. Similar arguments are used to prove God's power and uniqueness.
Another important argument for proof of the existence of God was the
ontological argument, advanced by
St. Anselm. Basically, it says that God has all possible good features. Existence is good, and therefore God has it, and therefore exists. This argument has been used in different forms by philosophers from Descartes forward.
The application of
Aristotelian logic is preceded by having the student memorize a rather large set of syllogisms. The memorization proceeded from diagrams, or learning a key sentence, with the first letter of each word reminding the student of the names of the syllogisms.
Each syllogism had a name, for example: "Modus Ponens" had the form of "If A is true, then B is true. A is true, therefore B is true."
Most university students of logic memorized Aristotle's 19 syllogisms of two subjects, permitting them to validly connect a subject and object. A few geniuses developed systems with three subjects, or described a way of elaborating the rules of three subjects.
As well as Aquinas, other important names from the medieval period include
Duns Scotus and
Pierre Abélard.
As with many periodizations, there are multiple current usages for the term "Modern Philosophy" that exist in practice. One usage is to date modern philosophy from the "
Age of Reason", where systematic philosophy became common, excluding
Erasmus and
Machiavelli as "modern philosophers". Another is to date it, the way the entire larger modern period is dated, from the
Renaissance. In some usages, "Modern Philosophy" ended in 1800, with the rise of Hegelianism and Idealism. There is also the
lumpers/splitters problem, namely that some works split philosophy into more periods than others: one author might feel a strong need to differentiate between "The Age of Reason" or "Early Modern Philosophers" and "The Enlightenment", another author might write from the perspective that 1600-1800 is essentially one continuous evolution, and therefore a single period. Wikipedia's philosophy section therefore hews more closely to centuries as a means of avoiding long discussions over periods, but it is important to note the variety of practice that occurs.
A broad overview would then have
Erasmus,
Francis Bacon,
Niccolò Machiavelli, and
Galileo Galilei represent the rise of empiricism and humanism in place of scholastic tradition.
17th-century philosophy is dominated by the need to organize philosophy on rational, skeptical, logical and axiomatic grounds, such as the work of
René Descartes,
Blaise Pascal, and
Thomas Hobbes. This type of philosophy attempts to integrate religious belief into philosophical frameworks, and, often to combat atheism or other unbeliefs, by adopting the idea of material reality, and the
dualism between spirit and material. The extension, and reaction, against this would be the monism of
George Berkeley and
Benedict de Spinoza. It was during this time period that the empiricism was developed as an alternative to skepticism by
John Locke,
George Berkeley and others. It should be mentioned that
John Locke,
Thomas Hobbes and
Edmund Burke developed their well known political philosophies during this time, as well.
The
18th-century philosophy article deals with the period often called the early part of "The Enlightenment" in the shorter form of the word, and centers on the rise of systematic empiricism, following after
Sir Isaac Newton's natural philosophy. Thus
Diderot,
Voltaire,
Rousseau,
Montesquieu,
Kant and the political philosophies embodied by and influencing the
American Revolution are part of
The Enlightenment. Other prominent philosophers of this time period were
David Hume and
Adam Smith, who, along with
Francis Hutcheson, were also the primary philosophers of the
Scottish Enlightenment.
The
19th century took the radical notions of self-organization and intrinsic order from Goethe and Kantian metaphysics, and proceeded to produce a long elaboration on the tension between systematization and organic development. Foremost was the work of
Hegel, whose
Logic and
Phenomenology of Spirit produced a "dialectical" framework for ordering of knowledge. The 19th century would also include
Schopenhauer's negation of the will. As with the 18th century, it would be developments in science that would arise from, and then challenge, philosophy: most importantly the work of Charles Darwin, which was based on the idea of organic self-regulation found in philosophers such as
Adam Smith, but fundamentally challenged established conceptions.
Contemporary philosophy
The
20th century deals with the upheavals produced by a series of conflicts within philosophical discourse over the basis of knowledge, with classical certainties overthrown, and new social, economic, scientific and logical problems. 20th century philosophy was set for a series of attempts to reform and preserve, and to alter or abolish, older knowledge systems. Seminal figures include
Sigmund Freud,
Friedrich Nietszche,
Ernst Mach,
John Dewey. Epistemology and its basis was a central concern, as seen from the work of
Heidegger,
Karl Popper,
Claude LĂ©vi-Strauss and
Bertrand Russell. Phenomenologically oriented metaphysics undergirded
existentialism (
Jean-Paul Sartre,
Søren Kierkegaard,
Albert Camus) and finally
poststructuralism (
Gilles Deleuze,
Jean-François Lyotard,
Michel Foucault,
Jacques Derrida). Also notable was the rise of "pop" philosophers who promulgated systems for dealing with the world but were isolated philosophically, including
Ayn Rand,
C. S. Lewis and others.
In
the West, the term
Eastern philosophy refers very broadly to the various
philosophies of "the East," namely
Asia, including
China,
India,
Japan,
Persia and the general area. One must take into account that this term ignores that these countries do not belong to a single culture.
Indian philosophy
See articles Indian philosophy, Hindu philosophy and Hinduism (section Hindu philosophy: the six Vedic schools of thought)Persian philosophy
See articles Iranian philosophy and ZoroastrianismChinese philosophy
See article Chinese philosophyBuddhist philosophy
See article Buddhist philosophyJewish philosophy
See article Jewish philosophyChristian philosophy
See article Christian philosophyIslamic philosophy
See article Islamic philosophy*
The history of religious and philosophical ideas, in ''Dictionary of the History of Ideas
