Figure 1 (Professor Wu Guosheng, Department of Science History, Tsinghua University)

On the evening of November 7th, 2019, Lecture 2 of the "Science and Civilization" academic series was held in the B101 lecture hall of the second gymnasium of Peking University. Professor Wu Guosheng from Tsinghua University gave an academic lecture, entitled “The Origin of Greek Scientific Spirit”. The lecture was chaired byAcademician Han Qide, the head of theDepartment of History of Science, Technology and Medicine, Peking University

Before the lecture, Professor Han Qide reviewed the report " Philosophy, Seeking Truth orStrength”that Professor Wu Guosheng had made at the annual meeting of the History of Science, Technology. The spirit of modern science originated in Greece, and where did the spirit of science in ancient Greece come from. At that time, what role did political and economic society have in the generation of scientific spirit? The indroduction led to the theme of this lecture.

Professor Wu Guosheng came straight to the point and explained that he would analyze the origin of the scientific spirit of ancient Greece from three aspects: Greek science as a science of freedom; the origin of Greek science I: As the discovery of nature; the origin of Greek science II: the discovery of cosmos.

Modern Science and Traditional Science

Professor Wu Guosheng believes that the introduction of modern science into China is a process of forced acceptance, with a historical background of salvation. Therefore, when Chinese people accept and study Western science, they pay more attention to way of doing it, and ignore the thinking of science. The understanding of science is still blank.

We have many misunderstandings about Greek science. One of the main misunderstandings is to understand Greek science in accordance with the definition of modern science. In this sense, there was no "science" in ancient Greece. Professor Wu Guosheng disagrees with this statement, because modern science originates from the ancient Greek “useless” science. He quoted Einstein's points of view that he two major sources of modern science are: first, the deductive science represented by the "Elements of Geometry" of Euclid, created by the Greeks; second, the method of experiment-to-causation. To some extent, Greek science shared a half of the genes of modern science. According to Einstein, Greek science pioneered a deductive and reasoning way of thinking. Chinese ancient thoughts (such as Mohists) also had reasoning, but it was still at an early stage. Only Greek science has developed pure, formal, deductive, reasoning, and demonstrative science on a large scale, which is called Greek science. The term Greek science is not only a concept of history, but also a type of science, as opposed to utilitarian modern science. Professor Wu Guosheng pointed out that Greek science has an unlimited imagination due to its non-utilitarian characteristics at the beginning; the difference between modern science and traditional science is that modern science creates demand, and the source of this idea is Greek science. Therefore, modern science cannot be disseminated widely, without deep understanding of the Greek scientific spirit. This is why we still have to pay attention to and study Greek science.

Three disciplines in Greek science deserve special attention and had a very important influence on modern science: deductive geometry, natural philosophy (physics), and cosmology-astronomy. Deductive geometry rigorously introduces the entire European geometric logic system, starting from the axiom and formula; Newton’s physics actually directly inherited Aristotle’s physics tradition; and Copernicus ’astronomical revolution also inherited ancient Greek astronomical tradition.

The following analysis will focus on these three disciplines.

Greek science as a science of freedom: the embodiment of deductive geometry

The Greek geometry, from the noun to the reality, is all from Egypt. Egyptian measurement is the science of measuring (a practical technique). Greece transformed it into a kind of reasoning about "theentity ". In ancient Greece, the proliferation of reasoning had a lot to do with the pursuit of freedom and humanity.

Professor Wu Guosheng compared Chinese tradition with Greek tradition. China is a farming nation, and our cultural characteristics are settlement culture, acquaintance culture, and family culture, emphasizing on interpersonal relationships. Therefore, ethics is the first knowledge. The Confucian thought of "rites" predestined the cultural orientation of the Chinese nation. The Four Books and Five Classics and the Tang Poetry and Song Ci belongs to the study of rites, even the astronomy. Meanwhile, Greece is a nomadic and migrant nation. This characteristic has created a contractual society, paying more attention to the individual, autonomy, consciousness, and self-sufficiency. Therefore, freedom has become the supreme ideal of human nature in Western culture. The benevolent of the East and the freedom of the West form a stark contrast in human ideals. Just as the benevolent ideal of human nature creates the "ritual" culture, the ideal of freedom creates a Greek type of science, a science of conserving and educating the human nature of freedom. Therefore, Greek science abandoned the application and utility of science when it first appeared.

Aristotle believes that science and knowledge can be graded. The lowest level is experience, knowing only the how, but not the why; the higher level is skill, knowing the how and the why; the highest level is science. The characteristic of science is that it surpasses the goal of application, focusing only on the self-development of knowledge itself. This is a Greek tradition that directly serves the Greek cultivation of freedom. The so-called freedom means focusing on oneself, achieving one's own recognition and identification, and casting it into a personality ideal and a core value of civilization. It can be achieved by studying science, the science of internal deduction only for its own purposes. This is the first characteristic of Greek science as a free science, purely serving itself and lacking utilitarian purposes. It is knowledge that exists for its own purposes and it is "useless" knowledge.

The second characteristic of Greek science as a free science is that it does not rely on external experience and develops itself purely on the basis of internal deduction. Introducing oneself by oneself is a kind of true reasoning. To carry out true reasoning, we must first look for the invariants in the change. Only by finding the invariants can we develop deductions about ourselves.

Professor Wu Guosheng said that the axioms in Euclidean geometry are often "nonsense", such as the first theorem of Euclidean geometry, the equivalent is equal to the equivalent; the second theorem, equal plus equal is equal to the same. These seem to be "nonsense", but only "nonsense" can truly be true. Strictly speaking, all mathematical theorems become nonsense once proven, because they are always correct. The development process of "nonsense" in ancient Greece established a true reasoning system, which caused many problems, such as the famous Learning Paradox in ancient Greece. The attitude of the Greeks to the paradox is to be debated to the end. Learning the paradox quickly becomes a very critical factor for the Greeks to know about the nature of knowledge, which promotes the formation of the "recall theory" that everyone has innate knowledge and a priori knowledge, and learning is to awaken sleeping rationality. Therefore, geometry plays a very important role in the Greek Academy. It is said that there is a sign at the door of the Plato Academy called "Let None but Geometers Enter Here", which one without learning geometry is not fully human. The spirit of geometry is an important manifestation of the scientific spirit of Greece.

The origin of Greek science I: As the discovery of nature

There existed correlations as well as differences between nature and freedom. Freedom emphasized on human nature, the awakening of self-awareness indicated the beginning of the course of human civilization, while nature referred to things per se. The term "the discovery of nature" was proposed by Geoffrey Lloyd, the professor in History of Science of the University of Cambridge saying that the two major marks of the birth of Greek science were the discovery of nature and critical thinking.

Professor Wu Guosheng pointed out that "nature" was not an ancient Chinese vocabulary. Although "nature" was mentioned in ancient classics, for example, "nature" was mentioned for five times in "Lao Tzu/Tao-Te Ching", it did not refer to natural environment, but "its being what it is"(Waley译本). "The Law of the Tao is its being what it is"(道法自然) meant that the Tao learns from itself and the Tao is the top rule. While, "nature" in modern Chinese originated from the Japanese translation of “nature”. In terms of this, Zhang Dainian, the doyen of the Department of Philosophy, had already differentiated and analyzed in 1937.

The term "nature" might cause semantic confusion not only in Chinese context, but also in Western context. “Nature” had two meanings in Western context, corresponding to the two stages of "discovery", that is, instinct and origin, and the set of natural things. These two meanings did not emerge together, but experienced a process of development.

The first stage of the discovery of nature was taking nature as instinct. Here, Professor Wu Guosheng cited the opinions of several scholars. British historian Collingwood mentioned in his book "The Idea of Nature" that the term “physis” had only one meaning according to the opinions of early Greek scholars, that is, the root and instinct of things. In Aristotle's works, the interpretation of “physis” contained six meanings, including the growing of growths, seeds of growths, root of movement of natural things, materials, essence of natural things, and essence of anything. It could be roughly seen that this had gone through the process of transformation from "growth" to "instinct". Heidegger believed that “physis” was the secret of understanding Western culture, and nature was Greeks’ initial understanding of being, that is, the beginning of growth, emergence, and self-reliance, or being what it is and going on one’s own way. This understanding was strikingly similar to Lao Tzu’s view that "The Law of the Tao is its being what it is".

Greek scholars recognized that things had "self", which caused the self-splitting of being, and the splitting between "things" and "things themselves". How to understand it? Professor Wu Guosheng pointed out that things were diverse and changeable, while things themselves were single and permanent. The contradiction between the two formed the issue of phenomena and essence. What is the essence? It is the instinct of things themselves. Greek thoughts began to emphasize the instinct of things and pursued universality and persistence. It was the first transformation from "nature" to "essence".

Here, Professor Wu Guosheng also concluded the opinions of Greek scholars. All pre-Socratic philosophers were not divided into the realm of nature and the realm of personnel. What they all studied was the origin and instinct of all things, and they did not make a trisection into nature, society, and people. Natural philosophers were philosophers, nature was instinct and essence, and the pursuit of instinct was science. According to Heidegger’s views, metaphysics was physics. It was why philosophy was inseparable from science in Western fields. Philosophy was "meta-science" (meta- is the prefix meaning "after or beyond"), so that it followed science. The rhythm of science regulated the rhythm of philosophy.

Plato's transcendentalism. Plato believed that the instinct of natural things were not just natural things. Only the eidos were internal and self-expanding, while external things were not self-expanding. Plato believed that he adopted a transcendental attitude and guided the pursuit of the 15 nature to "transcendentalism". Natural things were unnatural, because they had been expelled from the internal realm. The "transcendental" eidos was the "internal" essence.

However, Aristotle brought the "transcendentalism" back to the "essentialism". He believed that regardless of the eidos or essence of things, they were always inside of the things but not outside of the things. Physics was the study of the instinct of all things; it is a study of “defining the instinct” and a system of the logics of conceptual categories of the instinct of things. Physics was study of "nature".

It was the first stage of the discovery of nature, that is, nature transformed into instinct and essence. During the second stage, nature further transformed into the second meaning, which introduced the concept of natural things.

Before Aristotle nature was the instinct of being, while Aristotle believed that nature was just the instinct of natural things. Natural things were different from manufactured things. In more detail, natural things were things with "internal" instinct, while manufactured things were things with "external" instinct. For example, the reason why trees could grow in the ground was relying on themselves but not external interference, so trees were natural things. In the meantime, tables would rot if thrown into the soil and would not turn into new ones. The existence of tables was caused by various external factors, so tables were manufactured things. Aristotle narrowed the scope of "nature", under which “nature” was no longer the essence of being but the essence of "natural things".

What above was the initial understanding of "nature" which experienced two times of transformations. Recently, it had undergone a third and larger transformation. Professor Wu said that the third transformation of nature was not involved in today's lecture, but he still briefly mentioned it. The emergence of Christianity had further subverted the status of natural things. Because natural things were also created by God, so that they also lost their own instinct as God's creations. Then how can we study nature? New method was developed, that is, doing trials through experience and experiments. This was also a key link from the science of seeking truth to the science of seeking strength, that is, nature lost itself.

Several transformations of nature had caused two kinds of debates on the concept of modern nature. The first was the "nature" in scientists’ eyes. What they believed was nature in the sense of Kant, which was a field of phenomena in accordance with the laws of mathematics artificially constructed by laboratories. The second was returning to nature. It was the essence of normative things, and the things themselves that returned to the previous concepts. The first meaning of nature was the concept having experienced three times of transformations, and the second returned to the concepts of Aristotle and Heidegger. This was the discovery of the concept of nature.

The origin of Greek science II: the discovery of cosmos

Professor Wu Guosheng believed that the term cosmos was the key to understanding Greek astronomy. The ancients’ understanding of the universe were different in the east and west, including sayings of Gai Tian, Hun Tian, Xuan Ye and, etc. The Greeks named the universe cosmos, which was opposite to chaos. It contained four meanings. First, they believed that the universe was a whole, a spherical and finite universe. Second, they believed that the universe was in order with center; the earth is centered, and the celestial spheres circled annularly. Third, the celestial spheres followed harmonious and specific mathematical ratio. Fourth, the universe was perfect; the celestial spheres revolved in uniform circular motion. It was a whole set of concepts of cosmos for Greeks. The Greeks believed that the universe as cosmos was tangible, finite, visible and arguable.

In terms of the opinion that the universe was tangible, Professor Wu Guosheng supposed that it was related to Greek mythology. Because the Greek deities had the same shape and sex as human beings; they had developed limbs and fit body. The Greeks worshipped deities as well as the perfection of shapes. The tangible characteristics of Greek deities enabled the Greeks to directly view the universe as a tangible thing. Similar to the tangible universe, the Greeks believed that all pure knowledge was a kind of "vision" to some extent. The original term of theory, “theoria”, meant "static viewing". Theory was viewing, and Plato's eidos served as the viewing object in the soul's eyes. Professor Wu Guosheng believed based on that eidos should be translated as "phase", and Plato regarded the transcending essential world as the world of phases.

In addition, theory of cosmos particularly favored spheres, and the Greeks' love for spheres was well-founded. Aristotle said that the sphere had the greatest inclusiveness and was most suitable as the shape of the universe. Parmenides said that all shapes were polyhedral, while the sphere has only one surface, so this "one" was the most suitable shape to become the only universe. Plato said that all the spheres were highly similar, which was the most suitable shape for the creation world. In addition, the sphere had the most set symmetry, under which the strictly geometric celestial sphere put the "center" in a striking position so that the "symmetry" was highlighted. It could be said that the sphere was the concentrated presentation of the Greeks’ preferences for geometry.

Here, Professor Wu Guosheng quoted the opinion of the French philosopher Vernant that theories of geometry were not only the characteristics of Greek scientific thoughts, but also the characteristics of its political and social thoughts. Theories of geometry presented a strong contrast with the ancient space concepts embodied in other myths and religious customs. The geometry of the circle originated from the politics of polis, while the Greek space concepts was transformed from a religious, descriptive and hierarchical space into a homogeneous and reversible geometric space. Polis civilization created a preference for the concept of homogeneous space. Polis was public political affairs, which meant a non-holy and rational process of social life, and every citizen in polis participated equally. In public, everyone had the same power and freely debated and expressed opinions, which became the normal state of polis life. The term logos derived from this debate referred to not only public speech but also rationality.

The center of the Greek polis was Agora but not the royal palace. Agora was a specific vocabulary in polis. There was no such similar building in China, so it was not easy to translate. Agora was both a public square and a trade fair. It was located at the middle of the Greek polis, and all people were about the same distance from it and could reach at the same time. It was believed to have been formed during the early war years in Greece. Agora's architecture embodied the tradition of ancient Greece that everyone was equal in terms of access to power; the geometry of circle embodied the symmetrical, balanced and equal political concepts.

Professor Wu Guosheng also pointed out that although the characteristics of the marine peoples helped the Greeks to find that the sea level was curved, geometric symmetry and equality was a very important factor for the guess of earth being the sphere of the Greeks, especially the preference for circles. Anaximander proposed that the ground was at the center, equidistant from each end, without moving towards any direction. He found that the things lying at the center of the universe did not move; they had no reason to move towards any direction. The "spherical" characteristic of the earth was confirmed until the astronauts in the 20th century flew into space and sent back photos of the earth. However, in about 500 BC or before, Greeks had already had the thought of "the earth is a sphere". The philosophical reason for this thought was geometry equality. Plato pointed out in the "Gorgias" that "geometric equality had great influence for both people and deities." Not only should people obey it, but also deities must obey the power of geometric equality.

Finally, Professor Wu Guosheng briefly summarized the main contents of the report. Greek science was science of freedom, and it was super-utilitarian and inherently deductive. Internality originated from the discovery of the "selfness" of things, and the discovery of "selfness" was the discovery of nature. The discovery of nature was inseparable from the education and moralization of the free human nature of Greece. The intangible and finite characteristics of the Greek deities were related to Plato’s eidos. The democratic mechanism of the polis civilization contributed to the aesthetic preference for circles. Through these aspects, Professor Wu linked the inner parts of Greek science together and explained the origins of Greek scientific spirit from the perspective of philosophy and history of thought.

After the report of Professor Wu Guosheng, Professor Han Qide gave comments. He highly praised Professor Wu Guosheng's demeanor as an authority in the science of philosophy. He thought that Professor Wu clearly restored the Greek scientific spirit from the aspects of science of freedom, the science of nature, and the discovery of cosmos. The contents were rich and thought-provoking. Finally, Professor Wu had an in-depth discussion with the audience on the contents of the lecture, involving human nature, the needs created by modern science, the theory of quantum physics violating instinct, and social paradox, and the atmosphere was very warm. The lecture ended in the active discussion.

Figure 2 Professor Wu Guosheng and Professor Han Qide