Plato and Aristotle(4th Century BC)柏拉图和亚里士多德（第四世纪公元前）.ppt

1、Plato and Aristotle (4th Century B.C.),1. The Crisis of the Polis,The end of the Peloponnesian War did not bring an end to confrontations among major Greek city-states. Sparta, Thebes, and eventually Athens competed for power and leadership of the Greek cities. The 4th century B.C. witnessed the shi

2、ft of power balance, and of political alliances. Warfare was constant. Persia, from time to time, would also get into the act and sometimes played a major role.,1. The Crisis of the Polis,Thebes became stronger than ever under the leadership of two intimate friends, Epaminondas and Pelopidas. In 371

3、 B.C. when the Spartans marched toward Thebes, the end of them as a major power in Greece came. The two armies were met at the plain of Leuctra. Theban Sacred Band and its novel tactics killed nearly half the Spartan present including their king. The remainder of the Spartan army withdrew. Spartan S

4、upremacy in hoplite warfare forever shattered. Theban army ravaged Laconia, setting free the helots.,1. The Crisis of the Polis,Within a few years and with comparatively little loss of life, Thebes accomplish what generations of Athenians could not. Sparta was finished as an international power. But

5、 this did not mean that the Thebans supremacy was assured. Thebans were unable to replace Athenians and Spartan imperialism with Theban imperialism. Ultimately, Thebes gained nothing for itself. By knocking out Sparta as military power, Epaminondas in fact did a great favor to Philip II of Macedon,

6、the future conqueror of Greece, which we will come back in the next chapter.,1. The Crisis of the Polis,Therefore, all the efforts of the various major Greek states aimed to extend their hegemony over mainland Greece in the first half of the fourth century ended in failure. By the mid 350 B.C., no G

7、reek city-state had the power to rule more than itself on a consistent basis.,2. Greek Phylosophy,The Greek word, philosophos means “a lover of wisdom”. It had been a tradition in ancient Greece that thinkers had taken pleasure in searching for principles underlying the cosmos and human life in it.

8、Democritus, for example, claimed that he would “rather find the explanation for a single phenomenon than gain the kingdom of Persia.” Ancient Greek thinkers devoted themselves to their pursuits in different shapes. The most famous Greek from this turmoil fourth century B.C. was not a politician or a

9、 general, but the Athenian philosopher, Plato, Socrates most brilliant pupil.,3. Pupils of Socrates,If a teacher be judged by the enduring greatness of his pupils, who can equal Socrates? Plato, who is the very foundation of philosophy. It has been said that all the western philosophy is but a serie

10、s of footnotes to Plato.,3. Pupils of Socrates,And Platos pupil Aristotle is the intellectual father of all the universities of the world today. And Xenophon, less influential, but a man of action as well as ideas, like Plato, devoted to his teacher. And all three of these intellectual figures were

11、forever molded by what happened on one single day in the year 399.,4. Plato,Born between 429 and 423 B.C., an aristocrat from one of Athens most distinguished families. As a member of the social elite, he was involved in politics at his young age. In 399 B.C., Plato was profoundly shaken by Socrates

12、 death, and ever since then, he forever retreated from Athenian public life.,Plato (c. 428-348),Socrates and Plato,4. Plato,Platos entire life reflected the influence of his teacher, Socrates. Over his lifetime, Plato composed numerous works called dialogues with settings and casts of conversational

13、ists. In most of those dialogues, Socrates played the principal part, talking about philosophical issues: What is beauty? What is piety? What is justice? What is love?,4. Plato,None of the conversationalists involved Plato himself. In other words, Plato never speaks in his own voice. Thus, scholars

14、differ as whether Plato had adopted Socrates as his mouthpiece and uses the words of “Socrates” to express his own thoughts.,4. Plato,But “Socrates” in his different dialogues changed over time, which probably indicates that Socrates might serve as a vehicle for Platos own ideas. In his dialogues, P

15、latos interests varied, ranging widely in political philosophy, astronomy, mathematics, and metaphysics.,5. Theory of Forms,Chief among Platos ideas was his Theory of Forms. Platos belief in Form is that the world as it seems to us is “not the real world, but only a shadow of the real world”. There

16、is an eternal, unchanging Form of everything, from sandals to triremes to sealing wax.,5. Theory of Forms,Forms are the abstract representations of the many types and properties of things we see all around us, like Goodness, Justice, Beauty, and Equality. Forms are invisible, invariable, and eternal

17、 entities, and are in the existence of a realm beyond the empirical world of human beings. We cannot perceive the Forms with our senses. It is only through reason that we acquire knowledge of Form.,5. Theory of Forms,Like the Forms, reason must be everlasting. But humans are not everlasting, and yet

18、 we are endowed to a limited extent with reason. Therefore, there must be some part of us that is everlasting, in which reason can reside. That part, Plato believes, is soul. This is Platos idea of the separation between immortal souls and human bodies. Influenced by Pythagoras, who, taught the doct

19、rine of the transmigration of souls which outlives the body. According to Plato, the soul brings with it knowledge of the Form.,5. Theory of Forms,Platos idea of the separation of soul and human body established the concept of dualism and this idea was appreciated in later philosophical and religiou

20、s writers, especially early Christian writers. Plato maintained that men should be in pursuit of perfect order and purity in their own souls by making rational desires control their irrational desires. The latter causes harm in various ways.,5. Theory of Forms,An often cited example is wine drinking

21、. A little drink of wine makes one feel comfortable; yet the excessive drinking of wine makes one crazy and suffer the hangover to come the next day. And thus, people who are governed by irrational desires thus fail to consider the future of both body and soul. Finally, since the soul is immortal an

22、d he body is not, our present, impure existence is only one passing phase in our cosmic existence.,Plato in his Academy,6. Platos Ideals,In his works dealing with the organization of society, Plato spoke bitterly of Athenian democracy, calling it the as “perverted form of government”. He believed th

23、at Pericles establishment of pay for service in public office had made the Athenians “lazy, cowardly, gabby, and greedy”.,6. Platos Ideals,Plato preferred what Aristotle and Isocrates later labeled “proportional” or “geometric” equality of democracy that accorded equal privilege to people of unequal

24、 merit. For Plato, giving equal political power to all alike was no different from giving all students the same grade regardless of their performance on papers and exams.,7. The Republic,Against the background of this fierce critique of his own city-state, Plato, in his most famous dialogue, The Rep

25、ublic, showed how human society should be constructed in ideal world. This work primarily concerns the nature of justice and the reasons that people should be just instead of unjust.,7. The Republic,Justice, Plato argues, is advantageous; it consists of subordinating the irrational to the rational i

26、n the soul. By using the truly just and therefore imaginary polis as a model for understanding this notion of proper subordination in the soul, Plato presents a vision of the ideal structure for human society as an analogy.,7. The Republic,Like a just soul, the just society would have its parts in p

27、roper hierarchy, parts that Plato in the Republic presents as three classes of people, as distinguished by their ability to grasp the truth of Forms.,7. The Republic,The highest class constitutes the rulers, or “guardians” as Plato calls them, who are educated in mathematics, astronomy, and metaphys

28、ics. Next come the “auxiliaries,” whose function it is to defend the polis. The lowest class is that of the producers, who grow the food and make the objects required by the whole population. Each part contributes to society by fulfilling its proper function.,7. The Republic,Women as well as men qua

29、lify to be guardians because they possess the same virtues and abilities as men, except for a disparity in physical strength between the average woman and the average man. The axiom justifying the inclusion of women that virtue is the same in women as in menis perhaps a notion that Plato derived fro

30、m Socrates. Never before in Western history had anyone proposed even in fantasy, which the imaginary city of the Republic certainly is that work be allocated in human society without regard to gender.,理想国又译作国家篇、共和国等，与柏拉图大多数著作一样以苏格拉底为主角用对话体写成，共分10卷，其篇幅之长仅次于法律篇，一般认为属于柏拉图中期的作品。这部“哲学大全”不仅是柏拉图对自己前此哲学思想的概

31、括和总结，而且是当时各门学科的综合，它探讨了哲学、政治、伦理道德、教育、文艺等等各方面的问题，以理念论为基础，建立了一个系统的理想国家方案。,理想国是西方政治思想传统的最具代表性的作品，通过苏格拉底与他人的对话，给后人展现了一个完美优越的城邦。 柏拉图把国家分为三个阶层：受过严格哲学教育的统治阶层、保卫国家的武士阶层、平民阶层。他鄙视个人幸福，无限地强调城邦整体、强调他一己以为的“正义”。在柏拉图眼中，第三阶层的人民是低下的，可以欺骗的。他赋予了统治者无上的权力，甚至统治者“为了国家利益可以用撒谎来对付敌人或者公民” 西方哲学家几乎都认为这篇对话是一部“哲学大全”。,理想国讨论的主题是正义问题

32、，首先讨论国家的正义。柏拉图认为一个好的国家应该具备智慧、勇敢、自制、正义这4种德性。,7. The Republic,Plato argues the best form of government ultimately, is one ruled by a philosopher-king. Until philosophers rule as kings or those who are now called kings and leading men genuinely and adequately philosophise, that is, until political powe

33、r and philosophy entirely coincide, while the many natures who at present pursue either one exclusively are forcibly prevented from doing so, cities will have no rest from evils,. nor, I think, will the human race.,8. Platos Practice,Hoping to realize this goal in an immediate and concrete manner, P

34、lato made three trips to Sicily in an attempt to educate a philosopher-king. But the experiment turned out to be futile. He also traveled in Italy, Egypt, and Cyrene. He then returned to Athens at the age of forty.,9. Platos Academy,Close to home, Plato founded the Academy, one of the earliest known

35、 organized schools in Western Civilization on his belief that knowledge could be taught to others. It received its name because of its location by the groves(树丛) of the ancient hero Academus. The Academy was not a school or college in the modern sense but rather an informal association of people, wh

36、o were interested in studying philosophy, mathematics, and theoretical astronomy with Plato as their guide.,9. Platos Academy,It is said that, over the entrance, the Academy had the following inscription: “Let no one unversed in geometry enter here.” The Academy became so famous as a gathering place

37、 for intellectuals that it continued to operate for nine hundred years. Until AD 529, Justinian I of Byzantium closed it, who saw it as a threat to the propagation of Christianity. Many intellectuals, including many famous philosophers, astronomers, mathematicians, and even scientists, were schooled

38、 in the Academy. The most prominent one is Aristotle.,10. Plato,The writings of Plato may be regarded as the origin of intellectual communication. The famous quote: “All philosophy is but a footnote to Plato” exemplifies the fact that Plato is the necessary starting point for any study of Western ph

39、ilosophy.,Part II: Aristotle,Together with Plato and Socrates, Aristotle (384 322 B.C.), a pupil of Plato, is one of the most important founding figures in Western philosophy. Born in Stageira, an Ionian city, in 384 B.C. His father Nicomachus was the royal personal physician to Macedon and so as a

40、boy, Aristotle was educated as a member of the aristocracy. At eighteen, Aristotle studied at Platos Academy in Athens and remained there for nearly twenty years, until after Platos death in 347 B.C.,Aristotle (384 322 B.C.),Aristotle,After he left the Academy, he travelled with his friends to Asia

41、Minor and took residence in its island Assos, where they together researched the botany (植物学)and zoology. Later on, he was invited by Philip II of Macedon to serve as tutor to his son Alexander.,Aristotle,Upon his returned to Athens in 335 B.C., he founded the great institution of scientific learnin

42、g at Athens, the Lyceum. Aristotle conducted courses at the school for the next twelve years. During this period, Aristotle composed many of his works. Upon Alexanders death, anti-Macedonian sentiment in Athens erupted. Aristotle was accused of impiety and then he fled the city, explaining, I will n

43、ot allow the Athenians to sin a second time against philosophy. He died the following year.,Aristotle,Over his lifetime, Aristotle studied almost every subject possible at the time, and also made significant contributions to most of them. In physical science, Aristotles interests included anatomy, a

44、stronomy, embryology, geography, geology, meteorology, physics and zoology. In philosophy, he contributed to aesthetics, ethics, government, metaphysics, politics, economics, psychology, rhetoric and theology.,Aristotle,He also devoted his studies to education, foreign customs, literature and poetry

45、. His combined works constitute a virtual encyclopedia of Greek knowledge. Therefore Aristotle was referred to as the last person who knew everything there was to be known in his own time.,Aristotle,Aristotle was the founder of formal logic. Aristotles works mostly survived in treatise form. In the

46、early 1st century AD, his logical works were compiled into six books which form the core of the logical theory, and his conception of it was the dominant form of Western logic until 19th century advances in mathematical logic.,Aristotle,Aristotle loved science. He grouped all science into three cate

47、gories: practical, poetical, or theoretical. By practical science, he means ethics and politics; by poetical science, he means the study of poetry and the other fine arts; by theoretical science, he means physics, mathematics and metaphysics.,亚里士多对科学的分类,（1）理论的科学(数学、自然科学和后来被称 为形而上学的第一哲学)； （2）实践的科学(伦理

48、学、政治学、经济学、战略学和修饰学)； （3）创造的科学，即诗学。,Aristotle,In the quest for understanding, Aristotle was never happier than in the meticulous observation. His stay in Asia Minor and the island Assos proved to be particularly rewarding to him because it afforded him opportunity for observing on life there. His writ

49、ings provide an account of many scientific observations, such as History of Animals and Generation of Animals.,Aristotle,He wrote, “The craftsmanship of nature provides extraordinary pleasures to those who are able to recognize the causes in things and who have a natural inclination to philosophy”.

50、Living things excited Aristotle and also inspired him the desire to classify them. Aristotles classification of living things contains some elements which were still in existence in the nineteenth century.,Plato and Aristotle,Aristotle,A well-known of Aristotle quote goes, “Plato is dear to me, but

51、dearer still is truth”. It, in fact, reveals a profound difference between Aristotle and his teacher, Plato. While Plato was happiest contemplating the eternal truths of mathematics, Aristotle thrived in the constantly changing world of nature. Plato, Aristotle thought, had failed to account for cha

52、nge. Quite differently, for Aristotle, the dynamic power of change accounted for a great deal of the excitement of mental life.,Aristotle,And not only this: It was movement toward a particular end teleology, that he saw as the guiding force behind life. A prime mover, he argued, shaped the universe

53、in accord with his ends. Only the prime mover itself was not itself moved. Loosely speaking, the prime mover was what most people would call god. Aristotles philosophy was very popular in Europe during the Middle Ages, when Thomas Acquinas (1225 -1274 AD) adapted it to Christian theology.,Aristotle,

54、Plato finds that the universal exists independent of particular things, and is related to them as their prototype. So for Plato, philosophic method means the descent from a knowledge of universal Forms to a contemplation of particular imitations of these. Aristotle found the universal in particular

55、things, which he called the essence of things. And so, for Aristotle, philosophic method implies the ascent from the study of particular phenomena to the knowledge of essences.,Aristotle,For Aristotle, form still refers to the unconditional basis of phenomena but is instantiated in a particular subs

56、tance. In a certain sense, Aristotles method is both inductive(归纳的) and deductive, while Platos is essentially deductive from a priori principles.,Aristotle,亚里士多德首先是个伟大的哲学家，他虽然是柏拉图的学生，但却抛弃了他的老师所持的唯心主义观点。 柏拉图认为理念是实物的原型，它不依赖于实物而独立存在。亚里士多德则认为实在界乃是由各种本身的形式与质料和谐一致的事物所组成的。“质料”是事物组成的材料，“形式”则是每一件事物的个别特征。就像是

57、现在有一只鼓翅乱飞的鸡，这只鸡的“形式”是它会鼓翅、会咕咕叫、会下蛋等。当这只鸡死时，“形式”也就不再存在，唯一剩下的就是鸡的物质。 柏拉图断言感觉不可能是真实知识的源泉。亚里士多德却认为知识起源于感觉。这些思想已经包含了一些唯物主义的因素。,Aristotle: The five elements,Fire, which is hot and dry. Earth, which is cold and dry. Air, which is hot and wet. Water, which is cold and wet. Aether(以太 ), which is the divine s

58、ubstance that makes up the heavenly spheres and heavenly bodies (stars and planets).,Aristotle: The five elements,Each of the four earthly elements has its natural place; the earth at the centre of the universe, then water, then air, then fire. When they are out of their natural place they have natu

59、ral motion, requiring no external cause, which is towards that place; so bodies sink in water, air bubbles rise up, rain falls, flame rises in air. The heavenly element has perpetual circular motion.,Aristotles Universe,Aristotle: Causality, The Four Causes,Material cause describes the material out of which something is composed. The formal cause tells us what a thing is, that any thing is determined by the definition, form, pattern, essence, whole, synthesis or archetype. The efficient cause is that from which the change or the ending of the change first starts. The final cause is that for