http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== Lecture 8 The new age of science in Greece. ------------------------------------------------------------------------ Introduction The beginning of civilization around 3000 BC coincided more or less with the end of the Stone Age. The period from about 3000 BC to about 1000 BC was characterized by the technology of bronze melting. Scientific progress during this period, known as the Bronze Age, was more or less synonymous with progress in astronomy, mathematics and the calendar. (Medicine and surgery were the other two areas where progress was being made, but before 1000 BC their link with science was tenuous at best, as the next lecture will show.) Science was practised by priests, and it remained inseparable from religion. Conditions during the bronze age were not stagnant, however. Technological developments included the development of the spoked wheel, which allowed the construction of lightweight chariots for courier services and battle. The invention of the pottery wheel introduced ceramic storage vessels of large size. The development of the block and tackle system allowed the lifting of large stones and as a consequence the introduction of large public buildings and palaces in regions where material for brick production was not available. A qualitative change occurred in Greece shortly after 1000 BC. The emerging Greek civilization broke the link between religion and science and established a new discipline for systematic attempts to understand and explain nature. The new discipline was called philosophy, literally "love of wisdom", and science was part of it. Why did the Greek scholars keep religion out of science? It has often been said that the Greek religion was not suitable as a tool to explain the natural world because it lacked the mystical depth and all-encompassing concept of other religions. Greek gods and goddesses were not almighty immortals in control of the universe. They did have more power than humans but were also prone to give in to temptation. They occasionally lusted after mortals and sometimes became mortals themselves for their misbehaviour. In their actions Greek gods were often closer to Superman than to the Sun Gods of the Egyptians or the Aztecs, who had the fate of the human race in their hands. In comparison to the religions of the great civilizations in the Indus and Nile valleys or in Mesopotamia the Greek religion was "more appropriate to the campfire than to the temple." (Williams, 1995) While this is certainly an accurate observation it still leaves another question unanswered. The character of the Greek religion was established well before 1000 BC. This is evident from Homer 's famous epics, the /Iliad/ and the /Odyssey,/ which were written during the 9th or 8th century BC and are full of gods that steal, commit adultery and deceive each other. This was a time when major technological developments came to Greece. Dorian nomads entered Greece from the north and brought the technology of iron forging and welding to their new homeland. Their arrival some time before 1000 BC marks the transition from Bronze Age to Iron Age. The technology of melting iron in a furnace, known in China from about 200 BC onwards, did not arrive in Europe until the 14th century AD, and early iron products were what is now called wrought iron or mild steel. It did not replace bronze for a long time. But iron ore is plentiful everywhere, and the techniques of forging and welding can be learnt by anyone. The introduction of iron implements thus revolutionized the daily lives of people. The plough in particular changed agriculture and allowed a sudden increase in population. Greece thus underwent great changes before 1000 BC. The development of science did not coincide with the beginning of the Iron Age. Thales of Miletus, the first of the philosophers who shaped the new era of science, lived some 500 years later. Why did science not emerge as a prominent characteristic of Greek civilization at the beginning of the Iron Age? Why did the simplicity of Greek religion not spark a new age of science 500 years before 600 BC? To answer that question we have to look at the development of Greek society from about 1000 BC to 400 BC. The development of Greek civilization As our timeline showed, the Greek civilization was preceded by the Minoan and Mycenaean civilizations on the island of Crete. We saw in Lecture 2 that the Minoan civilization excelled particularly in sea trade and could develop by building on whatever it found around the coast of the Mediterranean Sea. It experienced several major upheavals during its history. A major volcanic eruption with huge outfall of ash and a disastrous tsunami around 1500 BC was followed by a conquest of Crete only fifty years later. The conquerors came from mainland Greece, and as the Minoan empire slowly recovered, its influence expanded into the mainland by establishing close links with Mycenae <../maps/greece.jpg>, which became the centre of a new civilization. Imposing palaces sprung up in Knossos and other cities on Crete and on the mainland, testifying for the consolidation of power of a ruling aristocracy. Archeological excavations show that the Mycenaean civilization came to an end at about 1200 BC. Most of the palaces were burnt, apparently at about the same time. The reasons for this are not clear; but the period 1200 - 900 BC is often referred to as the "Dark Age" of Greece because life during these 300 years did not produce the same monumental buildings and delicate artefacts as the years before and after. But time did not stand still, and what happened during these years laid the basis for the civilization that followed. Geographically Greece does not offer the same good conditions for agriculture as the great river valleys of the Nile in Egypt or the Euphrates and Tigris in Mesopotamia. The Greek poet Hesiod, who lived around 700 BC, described his father's land as "cold in winter, hot in summer, good at no time." The peasants were usually poor and fell easily in debt with the land owners. As time went on, many of them lost their land and became slaves. This process established a feudal society with an aristocracy as its ruling class, not very different from conditions in many other agricultural societies. But much of Greece consists of mountainous terrain that cannot support rich agriculture. Athens, for example, grew to over 300,000 inhabitants during the 5th century BC and could not be fed from the surrounding land; it relied on sea trade and the export of olive oil, pottery and silver to feed its population. This created a new merchant class, which by about 800 - 700 BC had become very wealthy. The importance of the new class is evident from the fact that between 900 and 600 BC all major Greek cities had established colonies (or more accurately trading outposts) all along the coast of the Mediterranean and Black Seas from Spain to Italy, Lebanon to North Africa, Anatolia to the Ukraine. The new class resented the fact that it remained excluded from power, even though its wealth often exceeded the wealth of the feudal aristocracy. To change that situation required a revolution, which is impossible to achieve without a power base. A rich merchant who wanted to gain power therefore had to gain the support of the ordinary people. This brought about the rise to power of the so-called tyrants, individuals who, being swept to power on a wave of popular uprising, installed themselves as autocratic rulers. The period of the tyrants did not last long. Cypselus, the first documented usurper of power, established himself as tyrant of Corinth in 650 BC. Twenty years later the legislation of Dracon in Athens guaranteed equality before the law and introduced "draconian" (harshest) measures to protect private property from usurpers. A new constitution drawn up by Solon in 594 BC abolished all peasant debt, guaranteed peasant ownership of land and established four classes of citizens according to income. This eliminated the need for further revolution and established the new social order. The Greek civilization arose from the base of Iron Age technology and "democracy" (literally "rule by the people"), as the new social order was called. The rise of democracy The development from feudalism to the Greek city states went into three directions. The region of the Peloponnese, which offered relatively good conditions for agriculture, was least affected by the sea trade, and its regional centre Sparta <../maps/greece.jpg> did not establish more than one small colony. Its aristocracy held on to its privileges, and Sparta became the bulwark of reaction. The ruling class (Spartans) provided the military service. The members of the working class (helots) were assigned to work for individual Spartans but always remained property of the state. Young Spartan men were held in camps under "spartan" (basic and uncomfortable) conditions; the killing of helots suspected of planning an uprising was a compulsory part of their training. In other cities the rise of tyrants had lead to the liberation of the peasants. Having lost the traditional supply of slave labour, the cities replaced it with slave imports from their colonial outposts overseas. Some were ruled by an oligarchy (literally "command of the few"), in which the government consisted of the assembly of the rich slave owners (oligarches). Others established a democracy, in which all decisions were taken by the assembly of all citizens. Women and slaves were not counted as citizens and therefore were not allowed to attend the democratic assembly. To give an idea of relative numbers, in the 5th century BC 148,000 of the 320,000 inhabitants of Athens were slaves. An important aspect of the democratic cities was the replacement of the mercenary army by a military of armed citizens . The fact that the people of the cities were armed eliminated the possibility of autocratic rule, but it also diminished the efficiency of the military, since the individual citizen tends to try and minimize his expenses for defence. The first major cities to arrive at a new order were the cities of Ionia <../maps/ionia.jpg>, the western seaboard of today's Turkey. Athens <../maps/greece.jpg> was the most prominent of the democratic cities on the mainland. Its new social order allowed a free man to gain public office without regard to wealth or class. All he had to do was impress the democratic assembly with a well thought-out speech and good argument. This required training, particularly for those whose parents could not afford a good education for their children. Speaking to an assembly of a few thousand men without a public address system was as much a physical effort as an intellectual challenge, and the art of rhetoric was highly regarded. The first /Academy/ to train the free men of Athens to speak in public and to teach them what to talk about was founded by Plato in 387 BC, followed by Aristotle's /Lyceum/ in 355. The Greek religion was particularly appropriate for the new social order. The idea of an all-mighty god in undisputed control of the universe is the religious equivalent of the autocratic ruler. A society that allows every free man to stand up in front of its fellow men and convince them through good argument is prepared to allow its gods the same privileges; it cannot imagine heaven more restrictive than earth. The Greek gods were therefore free to explore new ideas and make mistakes just as everyone else. The Athenian democracy posed a severe danger for the feudal order, which Sparta could not ignore. The Peloponnese War between Sparta and Athens began in 431 BC. The citizen armies of Athens and the other democratic cities were no match for Sparta's military might, and the war ended in 404 with the capitulation of Athens. The turbulent times created the conditions for the rise of the empire of Alexander the Great, the topic of Lecture 10. Early Greek science in Ionia From this overview of Greek history it is clear that important developments could be expected in all areas of life. Science was no exception and had really only one restriction: The new order was open for all free men, not for women, and not for slaves. But from the free men were sure to rise those who would teach others reason and good argument. We know their names, and we rightfully honour them for their work; but we should not forget that it was the development of society that allowed them to reach their achievements. Understanding the background and being aware of the conditions under which great scientists worked ensures that we can acknowledge their achievements as objectively as possible and avoid the simple-minded concept that history and science is determined by the genius of a few individuals. This does not belittle their standing as scientists - on the contrary, great scientists were shaped by their society like everyone else, but they were the ones who made the discoveries and had the groundbreaking ideas. The birthplace of the new science was Ionia <../maps/ionia.jpg>, the region along the east coast of the Aegean Sea. Today this region is part of Turkey, but 3000 years ago it was settled by Greek people and eyed by many powers as a region full of wealth. Its cities were closest to the old centres of civilization in Anatolia, Persia and Mesopotamia and were aware of their achievements and ideas. Its people were in the best position to meld the new Greek thirst for science with the scientific knowledge accumulated by others over centuries. The poetry of Xenophanes of Colophon , who was born in Ionia but had to leave his home town after it was conquered by Persia, is a vivid illustration of the meeting of minds in the Ionian cities during the 6th and 5th century BC. While he critized the Greek attitude to gods with a good dose of sarcasm and promoted the idea of God as universal and supreme, this did not keep him from adopting a philosophy about nature that did not require divine intervention. In his view all things in nature were made from earth and water. The three philosophers traditionally seen as the founding fathers of Greek science are Thales, his student Anaximander, and Anaximenes. All three lived and taught in Miletus <../maps/ionia.jpg> and concerned themselves with the essence of matter ("cosmology") and its relationship to the divine. Xenophanes was younger than Thales, so it is likely that he received his ideas about the nature of things from him. The questions Thales, Anaximander and Anaximenes asked are the same questions science asks today: * How did order emerge from chaos? * Did multitude and variety develop from simplicity, or is it the essence of nature from its beginning? * Is there a systematic relationship between form and matter? * How and why do things move and change? It is uncertain whether Thales wrote any works; if he did, none of it survived. But reports from later philosophers give a reasonably clear picture of his thoughts. According to Aristotle Thales challenged the prevailing idea of the four basic elements air, water, earth and fire and taught that the universe is made up of a single matter. In his view this single matter is water, or more accurately moisture, which in its various phases can turn into air, earth, and if further compressed into fire. Thales' younger contemporary Anaximenes agreed with the concept of a single matter but allocated this role to "aer" rather than water. When /aer/ is "most evenly distributed" it is the common, invisible air of the atmosphere. By condensation it becomes visible, first as mist or cloud, then as water, and finally as solid matter such as earth or stones. If further rarefied, it turns to fire. Anaximander , a student of Thales, replaced Thales' water and Anaximenes' /aer/ with the abstract concept of the infinite and introduced some form of dialectic principle that drives nature to continuous change. In his view hot and cold, dry and wet and other opposites constantly give way to each other to maintain an equilibrium. Anaximander was a brilliant observationalist, and many see in him the founder of European astronomy. Probably the best known of the Ionian philosophers was Pythagoras . The modern world associates his name mainly with his mathematical achievements, but he was mainly a religious teacher. When he was about 30 years of age Pythagoras spent some time in Egypt, where he had an opportunity to gain insight into the rules that governed Egyptian priesthood. This apparently made a great impression on him, as 18 years later he migrated to southern Italy to establish a religious order that became known as "the Pythagoreans." The order is a vivid demonstration of the process of separation between religion and science and the social upheaval of the time. In a radical break with tradition the order admitted women as members, a decision that caused it much conflict with authorities. One of its beliefs was that "at its deepest level, reality is mathematical in nature." It was convinced that the principle underlying the universe was not only order but beautiful order expressed in simple forms such as the circle and elegant number relationships. But the Pythagoreans soon split into two directions. The /akousmatikoi/ ("teachers of esoteric beliefs") stressed its religious character and teachings, such as the interaction of opposites as the main driving mechanism for the world and successive reincarnation of the individual until eventual purification. The /mathematikoi/ ("teachers of science") concentrated on number relationships and their applications in acoustics, geometry and astronomy. Greek science had cut itself free from religious preconceptions, but it was still philosophy of nature in the sense that it examined the grounds for fundamental beliefs. A good scientist was first and above all a good observationalist and secondly a good philosopher. Once an observation was reasonably explained there was no incentive to experiment any further. Experimentation was indeed not part of Greek science. The successes of the Pythagoreans in acoustic science demonstrate this quite well. Pythagoras played the lute, and he and his group observed the sequence of notes obtained by shortening the strings. Applying their mathematical skills they correctly derived the theory of the major, minor and 12-tone scale. But they restricted their musical works, which were extensive, to string instruments and were unable to transfer their findings to the operation of wind instruments, which would have required dedicated experimentation. The beginnings of Greek astronomy The area of science in which the Greek civilization could inherit a large amount of factual data was astronomy. The Babylonians needed accurate observations of the first appearance of the new Moon for their calendar and had accumulated and recorded a mass of observations. The Pythagoreans, driven by their conviction of a beautifully arranged cosmos (/kosmos:/ "the beautiful order of things"), tried to discover the harmonies (/harmonia:/ "fitting together") of the universe by contemplating the regular motions of the heavens. Their model of the universe contained the Earth as a globe revolving with the other planets around a central fire. It appears that at a late stage they equated the distances of the heavenly bodies to the known musical intervals, which resulted in the concept of the "harmony of the spheres" in which the movement of the heavenly bodies gives rise to a musical sound. In its core the philosophical-mathematical approach of the Pythagoreans was a move away from the search for the true character of nature to a description of its form. The late Pythagoreans would even regard form as the true essence of natural phenomena and claim that all existing objects are fundamentally composed of form and not of material substance. This had immense consequences for science. It caused Plato to urge astronomers to express observed phenomena through the perfect form of circular motion and led to a range of geometric models designed as tools for predicting planetary positions but not necessarily regarded as physical descriptions of the universe. We shall come across this aspect of science again and again through the centuries: the situation that a scientific theory is able to explain the phenomena but cannot give insight into the structure of matter. Eudoxus of Cnidus was the first to develop a model of the universe by sets of nesting concentric spheres. Using only uniform circular motions, Eudoxus could describe and predict the movement of the planets with considerable success. To explain why some planets sometimes appear to move back on their path over the sky he required four homocentric spheres for each planet and three each for the Sun and Moon and applied the concept of epicycles . His student Callippus added spheres to improve the theory, especially for Mercury and Venus. The role of Athens Eudoxus was the last great scientist to work and live in Ionia. Already during his lifetime the centre of scientific study and philosophy had shifted to Athens. The Ionian astronomer, scientist and philosopher Anaxagoras had moved to Athens already in 480 BC, about 80 years before Eudoxus' birth. At that time the Ionian scientific spirit was new to Athens, and Anaxagoras was accused of blasphemy when he stated that the Sun is an incandescent stone slightly larger than the Peloponnese. The fact that the emergence of science in Greece was part of the social revolution of the merchant class is well demonstrated through the activities of the philosopher-scientists themselves. The charge against Anaxagoras was more motivated by politics than by religion, since Anaxagoras had aligned himself with the politician Pericles, who was the real target of the attack. Many other scientists were also active in politics. Thales of Miletus was involved in an unsuccessful plan to build a federation of all Ionian cities. Socrates , a contemporary of Anaxagoras who had abandoned the study of science because in Athens it was synonymous with cosmological speculation, was tried and convicted for "corruption of the young" and "neglect of the gods whom the city worships and the practice of religious novelties." He was sentenced to death and died by drinking a cup of hemlock. Plato , who had learned to follow his conscience from Socrates, established his Academy in about 387 BC for the declared purpose to train future politicians and took an active role in consultancies of various kinds. Several members of the Academy were involved in the formulation of laws for various city-states. Plato's Academy has often been called the first university. Its activities covered philosophy and all known branches of science, ie mathematics, geometry, biology, natural history and rhetoric. Plato himself concentrated on ethics and did not devote much of his time to scientific problems. His philosophy of nature shows strong Pythagorean influence in his teaching that beyond the level of physical things is a spiritual realm of "Forms." Thus, there are Forms of stone, sheep, beauty, colour, compassion and many more, and every actual stone, sheep, beauty, colour or act of compassion is but an imperfect copy of its Form. Although Plato himself was not active in scientific investigation he valued it highly. In his Dialogue /Republic/ he recommends that rulers of city states should be guided by philosophers who have undergone 10 years of education in the sciences, followed by 5 years of education in "dialectic", ie the art of finding the truth through question and answer. Plato's influence in the sciences was indeed immense, and his standing through the centuries is evident from the fact that all of his writings have been preserved. For nearly 100 years all of the most important mathematical work was done by members or friends of the Academy. Eudoxus of Cnidus transferred his school to Athens to be able to cooperate with Plato. Plato's Academy continued for 800 years until it was closed as a "pagan institution" by the Roman emperor Justinian in 529 AD. The attitude of the early Christian church to science is the topic of Lecture 12. One of Plato's students was Heracleides Ponticus , one of the first proponents of the idea that matter is made up of small particles. This "atomism" existed for a considerable time parallel to the Ionian idea of the unity of all matter. The scientific tools of the time were of course inadequate to decide in favour of one or the other. In his astronomical work Heracleides realized that Mercury and Venus revolve around the Sun (and not around the Earth as postulated by Eudoxus) and suggested that the Earth rotates around its axis. The most famous of Plato's students, who determined scientific thinking for 2000 years, was Aristotle . After Plato's death Aristotle travelled around the Mediterranean and established new academies. At the age of 50 he returned to Athens and founded his /Lyceum/ as a rival institution to the Academy. Aristotle's interests covered all areas of knowledge from medicine to biology, astronomy, logic, philosophy of nature, psychology, ethics, politics, art and rhetoric. He accepted Eudoxus' homocentric spheres as the starting point for his cosmology and developed it into a series of some 55 spheres nested about the Earth, which was fixed at the centre. The theory of homocentric spheres cannot account for changes in the brightness of planets produced by variations of their distance from Earth. It also fails to explain why Venus is never observed more than about 48° and Mercury never more than about 24° from the Sun. Despite these shortcomings the Aristotelian view of the universe was accepted as correct, and during the Middle Ages departing views were regarded as heresy. In 1624, some 2000 years after Aristotle derived his theory, the Parliament of Paris still declared that attacks on Aristotle amounted to blasphemy and were punishable by death. It goes without saying that Aristotle cannot be blamed for the erroneous attitudes of people 2000 years later. Aristotle stood out from all other philosopher-scientists of his time through the width and breadth of his interests and his systematic teaching effort at his /Lyceum,/ from which we still have his extensive lecture notes. The basis of his work, in his own words , was that "credit must be given to observation rather than to theories, and to theories only insofar as they are confirmed by the observed facts." It remains the core principle of all science today. Greek scientists had no concept of gravity, so Aristotle postulated that the universe was divided into two qualitatively different realms. In the terrestrial realm, which reaches out to the Moon, all heavy bodies by their nature seek the centre and therefore move in a straight line downwards, while light bodies move naturally upward. In the celestial realm the natural form of motion is circular. Aristotle's Law of Constant Motion was a precursor of Newton 's Third Law, which states that "to every action there is an equal and opposite reaction." Aristotle postulated that a body in uniform motion is acted upon by two forces of equal strength and opposite direction. Motion, he argued, is proportional to the force that produces it and inversely proportional to the resistence of the medium through which it occurs. Because there can be no resistance without a medium, Aristotle argued that there can be no void and that the universe is filled by "ether". This is essentially the position on which Newton based his experiments before he changed his perception of nature in 1679 and developed his laws based on attractive and repulsive forces, which relegates friction to a secondary effect. Summary * Shortly before 1000 BC the technology of iron forging and welding came to Greece. * A new merchant class developed in the trading cities and their colonies. This led to a new society structure called democracy. * Holding a position of influence in the democracy required the ability to speak in public and demonstrate knowledge about the world. The emergence of science was thus the response to a new need of society. * The Greek religion of gods with human traits and faults suited the new society well. This helped the process of separation of religion and science and established the new discipline of philosophy. * The wave of new scientific activity between 600 BC and 300 BC addressed questions of the substance and structure of matter, the structure of the solar system and the universe, and the action of forces on bodies in motion. * Greek scientists were always philosophers and saw scientific study as a means for good government; many were active in politics themselves. * For a short period Athens became the centre of Greek science, exemplified by Plato's Academy and Aristotle's Lyceum. * The model of the universe developed in Greece and summarized and perfected by Aristotle became the accepted foundation of European science for 2000 years. Reference Williams, L. P. (1995) Science, the history of. /Encyclopędia Britannica/ 15th ed.. ------------------------------------------------------------------------ next lecture <../lecture9.html>