Western Philosophy


Western Philosophy (Greek philosophia, "love of wisdom"), the rational and critical inquiry into basic principles. Philosophy is often divided into four main branches: metaphysics(形而上学, 玄学), the investigation of ultimate reality; epistemology([哲]认识论), the study of the origins, validity, and limits of knowledge; ethics, the study of the nature of morality and judgment; and aesthetics, the study of the nature of beauty in the fine arts. As used originally by the ancient Greeks, the term philosophy meant the pursuit of knowledge for its own sake. Philosophy comprised all areas of speculative thought and included the arts, sciences, and religion. As special methods and principles were developed in the various areas of knowledge, each area acquired its own philosophical aspect, giving rise to the philosophy of art, of science, and of religion. The term philosophy is often used popularly to mean a set of basic values and attitudes toward life, nature, and society—thus the phrase "philosophy of life." Because the lines of distinction between the various areas of knowledge are flexible and subject to change, the definition of the term philosophy remains a subject of controversy. Western philosophy from Greek antiquity to the present is surveyed in the remainder of this article. For information about philosophical thought in Asia and the Middle East, see Chinese Philosophy; Islam; Buddhism; Daoism (Taoism); Confucianism; Indian Philosophy.

Greek Philosophy

Western philosophy is generally considered to have begun in ancient Greece as speculation about the underlying nature of the physical world. In its earliest form it was indistinguishable from natural science. The writings of the earliest philosophers no longer exist, except for a few fragments cited by Aristotle in the 4th century bc and by other writers of later times.

The Ionian (爱奥尼亚人的)School

The first philosopher of historical record was Thales, who lived in the 6th century bc in Miletus, a city on the Ionian coast of Asia Minor. Thales, who was revered by later generations as one of the Seven Wise Men of Greece, was interested in astronomical, physical, and meteorological phenomena. His scientific investigations led him to speculate that all natural phenomena are different forms of one fundamental substance, which he believed to be water because he thought evaporation and condensation to be universal processes. Anaximander, a disciple of Thales, maintained that the first principle from which all things evolve is an intangible, invisible, infinite substance that he called apeiron, "the boundless." This substance, he maintained, is eternal and indestructible. Out of its ceaseless motion the more familiar substances, such as warmth, cold, earth, air, and fire, continuously evolve, generating in turn the various objects and organisms that make up the recognizable world.

The third great Ionian philosopher of the 6th century bc, Anaximenes, returned to Thales's assumption that the primary substance is something familiar and material, but he claimed it to be air rather than water. He believed that the changes things undergo could be explained in terms of rarefaction (thinning) and condensation of air. Thus Anaximenes was the first philosopher to explain differences in quality in terms of differences in size or quantity, a method fundamental to physical science.

In general, the Ionian school made the initial radical step from mythological to scientific explanation of natural phenomena. It discovered the important scientific principles of the permanence of substance, the natural evolution of the world, and the reduction of quality to quantity.

The Pythagorean (毕达哥拉斯的)School

About 530 bc at Croton (now Crotona), in southern Italy, the philosopher Pythagoras founded a school of philosophy that was more religious and mystical than the Ionian school. It fused the ancient mythological view of the world with the developing interest in scientific explanation. The system of philosophy that became known as Pythagoreanism combined ethical, supernatural, and mathematical beliefs with many ascetic rules, such as obedience and silence and simplicity of dress and possessions. The Pythagoreans taught and practiced a way of life based on the belief that the soul is a prisoner of the body, is released from the body at death, and migrates into a succession of different kinds of animals before reincarnation into a human being. For this reason Pythagoras taught his followers not to eat meat. Pythagoras maintained that the highest purpose of humans should be to purify their souls by cultivating intellectual virtues, refraining from sensual pleasures, and practicing special religious rituals. The Pythagoreans, having discovered the mathematical laws of musical pitch, inferred that planetary motions produce a "music of the spheres," and developed a "therapy through music" to bring humanity in harmony with the celestial spheres. They identified science with mathematics, maintaining that all things are made up of numbers and geometrical figures. They made important contributions to mathematics, musical theory, and astronomy.

Socratic (苏格拉底[哲学]的)Philosophy

Perhaps the greatest philosophical personality in history was Socrates, who lived from 469 to 399 bc. Socrates left no written work and is known through the writings of his students, especially those of his most famous pupil, Plato. Socrates maintained a philosophical dialogue with his students until he was condemned to death and took his own life. Unlike the Sophists, Socrates refused to accept payment for his teachings, maintaining that he had no positive knowledge to offer except the awareness of the need for more knowledge. He concluded that, in matters of morality, it is best to seek out genuine knowledge by exposing false pretensions. Ignorance is the only source of evil, he argued, so it is improper to act out of ignorance or to accept moral instruction from those who have not proven their own wisdom. Instead of relying blindly on authority, we should unceasingly question our own beliefs and the beliefs of others in order to seek out genuine wisdom.

Socrates taught that every person has full knowledge of ultimate truth contained within the soul and needs only to be spurred to conscious reflection to become aware of it. In Plato's dialogue Meno, for example, Socrates guides an untutored slave to the formulation of the Pythagorean theorem, thus demonstrating that such knowledge is innate in the soul, rather than learned from experience. The philosopher's task, Socrates believed, was to provoke people into thinking for themselves, rather than to teach them anything they did not already know. His contribution to the history of thought was not a systematic doctrine but a method of thinking and a way of life. He stressed the need for analytical examination of the grounds of one's beliefs, for clear definitions of basic concepts, and for a rational and critical approach to ethical problems.

Platonic Philosophy

Plato, who lived from about 428 to 347 bc, was a more systematic and positive thinker than Socrates, but his writings, particularly the earlier dialogues, can be regarded as a continuation and elaboration of Socratic insights. Like Socrates, Plato regarded ethics as the highest branch of knowledge; he stressed the intellectual basis of virtue, identifying virtue with wisdom. This view led to the so-called Socratic paradox that, as Socrates asserts in the Protagoras, "no man does evil voluntarily." (Aristotle later noticed that such a conclusion allows no place for moral responsibility.) Plato also explored the fundamental problems of natural science, political theory, metaphysics, theology, and theory of knowledge, and developed ideas that became permanent elements in Western thought.

The basis of Plato's philosophy is his theory of Ideas, also known as the doctrine of Forms. The theory of Ideas, which is expressed in many of his dialogues, particularly the Republic and the Parmenides, divides existence into two realms, an "intelligible realm" of perfect, eternal, and invisible Ideas, or Forms, and a "sensible realm" of concrete, familiar objects. Trees, stones, human bodies, and other objects that can be known through the senses are for Plato unreal, shadowy, and imperfect copies of the Ideas of tree, stone, and the human body. He was led to this apparently bizarre conclusion by his high standard of knowledge, which required that all genuine objects of knowledge be described without contradiction. Because all objects perceived by the senses undergo change, an assertion made about such objects at one time will not be true at a later time. According to Plato, these objects are therefore not completely real. Thus, beliefs derived from experience of such objects are vague and unreliable, whereas the principles of mathematics and philosophy, discovered by inner meditation on the Ideas, constitute the only knowledge worthy of the name. In the Republic, Plato described humanity as imprisoned in a cave and mistaking shadows on the wall for reality; he regarded the philosopher as the person who penetrates the world outside the cave of ignorance and achieves a vision of the true reality, the realm of Ideas. Plato's concept of the Absolute Idea of the Good, which is the highest Form and includes all others, has been a main source of pantheistic and mystical religious doctrines in Western culture


During the 1st century ad the Jewish-Hellenistic philosopher Philo of Alexandria combined Greek philosophy, particularly Platonic and Pythagorean ideas, with Judaism in a comprehensive system that anticipated Neoplatonism and Jewish, Christian, and Muslim mysticism. Philo insisted that the nature of God so far transcended (surpassed) human understanding and experience as to be indescribable; he described the natural world as a series of stages of descent from God, terminating in matter as the source of evil. He advocated a religious state, or theocracy, and was one of the first to interpret the Old Testament for the Gentiles.

Neoplatonism, one of the most influential philosophical and religious schools and an important rival of Christianity, was founded in the 3rd century ad by Ammonius Saccus and his more famous disciple Plotinus. Plotinus based his ideas on the mystical and poetic writings of Plato, the Pythagoreans, and Philo. The main function of philosophy, for him, is to prepare individuals for the experience of ecstasy, in which they become one with God. God, or the One, is beyond rational understanding and is the source of all reality. The universe emanates from the One by a mysterious process of overflowing of divine energy in successive levels. The highest levels form a trinity of the One; the Logos, which contains the Platonic Forms; and the World Soul, which gives rise to human souls and natural forces. The farther things emanate from the One, according to Plotinus, the more imperfect and evil they are and the closer they approach the limit of pure matter. The highest goal of life is to purify oneself of dependence on bodily comforts and, through philosophical meditation, to prepare oneself for an ecstatic reunion with the One. Neoplatonism exerted a strong influence on medieval thought.

IV Medieval Philosophy

During the decline of Greco-Roman civilization, Western philosophers turned their attention from the scientific investigation of nature and the search for worldly happiness to the problem of salvation in another and better world. By the 3rd century ad, Christianity had spread to the more educated classes of the Roman Empire. The religious teachings of the Gospels were combined by the Fathers of the Church with many of the philosophical concepts of the Greek and Roman schools. Of particular importance were the First Council of Nicaea in 325 and the Council of Ephesus in 431, which drew upon metaphysical ideas of Aristotle and Plotinus to establish important Christian doctrines about the divinity of Jesus and the nature of the Trinity.

Augustinian (奥古斯丁教义的),Philosophy

Saint Augustine (354-430), greatest of the Latin Fathers and one of the most eminent Western Doctors of the Church. Saint Augustine during the late 4th and early 5th centuries. the Neoplatonists, he considered the soul a higher form of existence than the body , predestination original sin, grace, and predestination: the "city of God," or community of saints, happiness is impossible in the world of the living, where even with good fortune, which is rare, awareness of approaching death would mar any tendency toward satisfaction. He believed further that without the religious virtues of faith, hope, and charity, which require divine grace to be attained, a person cannot develop the natural virtues of courage, justice, temperance, and wisdom. His analyses of time, memory, and inner religious experience have been a source of inspiration for metaphysical and mystical thought.

The only major contribution to Western philosophy in the three centuries following the death of Augustine in ad 430 was made by the 6th-century Roman statesman Boethius, who revived interest in Greek and Roman philosophy, particularly Aristotle's logic and metaphysics. In the 9th century the Irish monk John Erigena developed a pantheistic interpretation of Christianity, identifying the divine Trinity with the One, Logos, and World Soul of Neoplatonism and maintaining that both faith and reason are necessary to achieve the ecstatic union with God.

Even more significant for the development of Western philosophy was the early 11th-century Muslim philosopher Avicenna. His work modifying Aristotelian metaphysics introduced a distinction important to later philosophy between essence (the fundamental qualities that make a thing what it is—the treeness of a tree, for example) and existence (being, or living reality). He also demonstrated how it is possible to combine the biblical view of God with Aristotle's philosophical system. Avicenna's writings on logic, mathematics, physics, and medicine remained influential for centuries.

The most important medieval philosopher was Saint Thomas Aquinas

Aquinas made many important investigations into the philosophy of religion, including an extremely influential study of the attributes of God, such as omnipotence, omniscience, eternity, and benevolence. He also provided a new account of the relationship between faith and reason, arguing against the Averroists that the truths of faith and the truths of reason cannot conflict but rather apply to different realms. The truths of natural science and philosophy are discovered by reasoning from facts of experience, whereas the tenets of revealed religion, the doctrine of the Trinity, the creation of the world, and other articles of Christian dogma are beyond rational comprehension, although not inconsistent with reason, and must be accepted on faith. The metaphysics, theory of knowledge, ethics, and politics of Aquinas were derived mainly from Aristotle, but he added the Augustinian virtues of faith, hope, and charity and the goal of eternal salvation through grace to Aristotle's naturalistic ethics with its goal of worldly happiness.

Medieval Philosophy After Aquinas阿奎奈(意大利中世纪神学家和经院学家, 1226-1274)

In the 15th and 16th centuries a revival of scientific interest in nature was accompanied by a tendency toward pantheistic mysticism—that is, finding God in all things. The Roman Catholic prelate Nicholas of Cusa anticipated the work of the Polish astronomer Nicolaus Copernicus in his suggestion that the Earth moved around the Sun, thus displacing humanity from the center of the universe; he also conceived of the universe as infinite and identical with God. The Italian philosopher Giordano Bruno, who similarly identified the universe with God, developed the philosophical implications of the Copernican theory. Bruno's philosophy influenced subsequent intellectual forces that led to the rise of modern science and to the Reformation.

V.Modern Philosophy

Mechanism and Materialism

Descartes resolved to reconstruct all human knowledge on an absolutely certain foundation by refusing to accept any belief, even the belief in his own existence, until he could prove it to be necessarily true. In his so-called dream argument, he argued that our inability to prove with certainty when we are awake and when we are dreaming makes most of our knowledge uncertain. Ultimately he concluded that the first thing of whose existence one can be certain is oneself as a thinking being. This conclusion forms the basis of his well-known argument, "Cogito, ergo sum" ("I think, therefore I am"). He also argued that, in pure thought, one has a clear conception of God and can demonstrate that God exists. Descartes argued that secure knowledge of the reality of God allowed him to have his earlier doubts about knowledge and science.

Despite his mechanistic outlook, Descartes accepted the traditional religious doctrine of the immortality of the soul and maintained that mind and body are two distinct substances, thus exempting mind from the mechanistic laws of nature and providing for freedom of the will. His fundamental separation of mind and body, known as dualism, raised the problem of explaining how two such different substances as mind and body can affect each other, a problem he was unable to solve that has remained a concern of philosophy ever since. Descartes's thought launched an era of speculation in metaphysics as philosophers made a determined effort to overcome dualism—the belief in the irreconcilable difference between mind and matter—and obtain unity. The separation of mind and matter is also known as Cartesian dualism after Descartes.

Kant's writings constituted a high point of the Enlightenment, a fertile intellectual and cultural period that helped stimulate the social changes that produced the French Revolution (1789-1799). Other leading thinkers of this movement included Voltaire, Jean Jacques Rousseau, and Denis Diderot. Voltaire, developing the tradition of Deism begun by Locke and other liberal thinkers, reduced religious beliefs to those that can be justified by rational inference from the study of nature. Rousseau criticized civilization as a corruption of humanity's nature and developed Hobbes's doctrine that the state is based on a social contract with its citizens and represents the popular will. Diderot published a 35-volume work known as the Encyclopédie to which many scientists and philosophers contributed. Diderot and his Encyclopedists, as they were known, associated the progress and the happiness of humankind with science and knowledge, whereas Rousseau criticized such ideas along with the very notion of civilization.