Thales of Miletus

Greek philosopher

• Born: c. 624 b.c.e.
• Birthplace: Miletus, Ionia, Asia Minor (now in Turkey)
• Died: c. 548 b.c.e.
• Place of death: Miletus, Ionia, Asia Minor (now in Turkey)

Through his various theories, Thales countered supernatural and mythical explanations of nature, attempting to replace them with empirically derived answers. He became a transitional figure between the worlds of philosophy and science.

Early Life

Few details are known about the life of the man many call “the father of philosophy.” Ancient tradition often fixed a person’s birth date by a major event. According to Apollodorus, an Athenian historian of the second century b.c.e., the major event in the life of Thales (THAY-leez) was the solar eclipse of 585-584 b.c.e., when he was forty years old. If this is correct, Thales was born c. 624. He was a member of a distinguished family from the port city of Miletus, Ionia, on the west coast of Asia Minor. Thales’ upper-class background meant that he had the luxury of spending his life engaged in intellectual pursuits.

Although probably from Phoenicia originally, Thales’ family most likely lived in Miletus for several generations. Besides his social standing, his place of birth is also significant. Miletus was the major trading center of the Aegean Sea in the sixth century b.c.e. The coastal city entertained merchants from Egypt, Greece, and the Persian Empire. It possessed both a frontier spirit and a cosmopolitan, intellectual environment. A thriving economic center with a rich mixture of Near Eastern and Greek cultures, Miletus had no traditional, government-imposed beliefs that it sanctioned; life in Miletus was unconventional.

The body of knowledge familiar to the young Thales came principally from two sources: the earliest Greek writers and the scholars of Egypt and Babylon. Their ideas played a significant role in the philosophy of Thales, not because of their influence on him but rather because of his departure from them. Among the first ideas Thales encountered were those from the writings of Homer and Hesiod. Both these Greek writers speculated on the origins of the world and certain natural phenomena. Their answers, however, were always found within the realm of the Olympian gods. Homer and Hesiod did gather some factual data that they incorporated into their writings, but scientific advancement was impossible as long as nature was interpreted as the supernatural caprices of the gods. Greek thinkers before Thales had some knowledge of natural occurrences but never moved toward a more rational analysis. Theirs was an anthropomorphic world. Mythology served as both science and history prior to the revolution in thought that occurred in Miletus during the mid-sixth century.

The other information common to scholars such as Thales came from the Near East. The ancients of Egypt and Babylon had long experimented with their own forms of science and mathematics. The wonders of the Egyptian pyramids and other structures interested the Ionians, and the Babylonians claimed the attention of scholars for their study of the stars. While the achievements of these Near Eastern civilizations were remarkable, they were also limited in their scope. The Egyptians never converted their practical knowledge of mathematics and engineering into theories and principles. The Babylonians compiled volumes of notes on the heavens and developed astrology, a discipline hardly resembling astronomy. This was the intellectual climate, complete with preconceptions and misconceptions about natural “science,” into which Thales was born.

Life’s Work

The philosophy Thales espoused must be gleaned from the excerpts and comments of other authors. Herodotus, Aristotle, and Diogenes are the most notable ancient writers who included Thales in their works, and Thales’ contributions are represented consistently in all three accounts. Thales bridged the gap between superstition and reason. Aristotle credited Thales with being the first recorded Milesian in a line of pre-Socratic philosophers who attempted to define nature in terms of nature itself. The questions Thales asked and the assumptions he proposed changed philosophy and science and laid a rational foundation on which others could build.

Thales searched for the “stuff,” as the ancients referred to it, which composed all existing matter. He assumed that among the infinite variety of things on Earth there must be one underlying source of their existence. Though the stuff might change its form, it essentially retained its properties. Through observation, Thales concluded that the first principle of the world must be water. It was the prime substance of all things, and Earth floated on a cushion of it.

The matter of Thales’ theory also possessed the quality of fluidity. It was to some degree alive and caused the change perceived in the visible world. Thales compared the inner power of water to a magnet that moves a piece of iron. This animism was typical of sixth century philosophy. It compelled Thales to conclude that all things are “full of gods.” Although he used religious language, Thales did not adhere to a prevalent religious system—nor did he attempt to deify water in the traditional sense of ancient custom. To Thales, that which gave continual life must, in the vernacular of the time, be to some extent divine. Water was that life-giving substance that, in one form or another, composed everything and thus merited the term “god,” not an anthropomorphic Olympian god but a new secular and rational god of Thales’ making.

There is no extant record of the reason Thales chose water as the stuff of the world. Certainly the importance of water was not lost on ancient people. Water was central in the mythology of Greece, Egypt, and Babylon as well as in the Hebrew creation account. Some historians suggest that these myths exerted the greatest influence on Thales. In the epics of the Near East, Earth rises out of primeval water. The principal focus of these myths, however, was the origin of the world, not a common substance underlying all things in the world. Thus, Thales probably did not draw from them. Further, none of the ancient commentators on Thales mentions any influence of Near Eastern thought on Ionian philosophy developing in the sixth century b.c.e.

Many modern scholars have asserted that there is a rational explanation for Thales’ choice of water. Because Thales’ theory was founded on observation only, not experimentation, the three phases of water would have been readily apparent to him. Water, appearing in such numerous forms, fits the description of the stuff that changes but is fundamentally constant. From the sources on Thales, however, it is never established that he even understood the three states of water.

Aristotle postulated another reason that led Thales to his conclusion. It is a variation of the rational explanation fashioned by modern scholars. Given the proximity of Aristotle to Thales, this may be the closest to the latter’s own thinking. As Aristotle suggested, there existed a close link in the ancient mind between water and life. There were the rivers and seas without which humans could not nourish themselves. Trees contained sap, and plants had liquid within their stems. Growth, and therefore change, was inextricably tied to water—and nowhere was this clearer than in the ancient world. Even the human body testified to the importance of moisture. From conception to death, water was an integral part of human existence. As Aristotle observed, when the body died two things occurred: It became cold, and it dried up. Even that which was hot and dry required water. A popular fifth century b.c.e. idea held that the sun drew water to itself for nourishment and then rained it back to Earth to complete the cycle. Whether myth or logic influenced Thales, his attempt to look outside the divine process for answers to the puzzles of nature was monumental. By so doing, he attributed an orderliness to the cosmos that had heretofore been regarded as the disorderly and mystical playground of the gods.

Contemporaries hailed Thales as a politician, diplomat, civil engineer, mathematician, and astronomer, but his achievements in those roles are uncertain. Among the more important feats attributed to Thales was his prediction of a solar eclipse in 585-584 b.c.e. During a significant battle between the Medes and Lydians, Thales is said to have forecast a solar eclipse that, when it occurred, caused such trepidation among the combatants that they ceased fighting and called a truce. The ancients certainly believed the tale, but modern scholars doubt that Thales could predict an eclipse (such a prediction requires sophisticated astronomical calculations). A more likely astronomical achievement attributed to Thales is his idea of steering ships by the constellation Ursa Minor.

Tradition also credits Thales with introducing Egyptian principles of geometry to Greece. In Egypt, Thales is said to have taken the practical knowledge of Egyptian scholars and devised a method for accurately measuring the pyramids by their shadows. Altogether, five theorems are attributed to Thales. It is impossible to know the exact contribution of Thales to mathematics; it is likely, however, that he made some fundamental discoveries that enabled later mathematicians to build a framework for a variety of theorems.

In the minds of his contemporaries, Thales was not only a philosopher but also a sage. The Greeks named him one of the Seven Sages, because he urged the Ionian states to unite lest they fall easy prey to the Persian Empire. Thales was so respected by his countrymen that it is difficult to determine to what extent the legends that surround him are apocryphal. In antiquity, attributing great discoveries or achievements to men with reputations for wisdom was a common practice. The ancient authors themselves often recorded conflicting accounts of the accomplishments of Thales. It seems that they chose whatever Thalesian story would substantiate the point they were trying to make. Whatever the veracity of the stories enveloping Thales, it seems logical that his reputation for rational thinking would spread from his cosmological interests to such fields as mathematics, astronomy, and politics.

Significance

Were all the legends surrounding Thales false, his speculations on the principal substance of the world would be enough to accord him special recognition. It is not the theory itself that is so significant but the revolution in thinking that it produced. Thales placed the study of nature on a new plane: He lifted it from the realm of the mythical to the level of empirical study. Scholars began to evaluate and analyze theories on the basis of the factual data available. Thales was the first of what has been called the Milesian group of the Ionian school of philosophy. Anaximander and Anaximenes, who followed him, produced more sophisticated philosophical systems, but they regarded Thales as the master.

To the modern scholar, the limitations of Thales’ thinking are apparent. There remained elements of anthropomorphism and mythology in the work of Thales and the other pre-Socratic philosophers. While Thales rejected a universe controlled by the gods with his assertion “all things are water,” he did not anticipate an atomic theory, as Democritus did. Thales attributed to nature an animism that prevented him from seeing it as a neutral agent in the world. In this sense, his ideas are less abstract than the ideas of those who came after him. Thales does not properly belong to the world of modern science, and yet he is equally misplaced when his ideas are classified with the cosmologies of Homer and Hesiod. Thales transcended, through rational analysis, the established supernatural explanations of nature, laying the foundation for major advances in philosophy and science in the following centuries.

Bibliography

Anglin, W. S. The Heritage of Thales. New York: Springer-Verlag, 1995. A textbook on the history, philosophy, and foundations of mathematics intended for undergraduate students.

Brumbaugh, Robert S. The Philosophers of Greece. New York: State University of New York Press, 1981. Evaluation of Greek philosophy from Thales to Aristotle. Takes a “romantic” approach to the subject that depicts Thales as a Renaissance man. Includes bibliography.

Burnet, John. Early Greek Philosophy. 1892. Reprint. London: A. and C. Black, 1963. Still considered one of the first major pieces on the subject. Emphasizes the Greeks as the earliest scientists and philosophers. Includes elaborate notes on source material.

Guthrie, William Keith Chambers. The Earlier Presocratics and Pythagoreans. Vol. 1 in A History of Greek Philosophy. New York: Cambridge University Press, 1978-1990. A standard general account of the subject, beginning with Thales and continuing through to the works of Heraclitus. Concentrates on how early Greek writers of myths and theogonies influenced the early ideas of the pre-Socratic philosophers and adheres to the traditional claim of Thales as the first European philosopher. Includes bibliography.

Hussey, Edward. The Presocratics. Indianapolis: Hackett, 1995. An introduction to early Greek thought, designed for the reader with no background in Greek. Deals with philosophy and science within the political and cultural setting of the ancient world and stresses the importance of political development on the emergence of the ideas of Thales. Includes maps and bibliography.

Nahm, Milton C., ed. Selections from Early Greek Philosophy. Englewood Cliffs, N.J.: Prentice-Hall, 1968. Short translated excerpts from the works of ancient authors in early Greek philosophy. Book spans the period from the Milesians through the atomists. Includes commentaries on Thales by Diogenes, Aristotle, and Plutarch.

Wightman, William P. D. The Growth of Scientific Ideas. Westport, Conn.: Greenwood Press, 1974. Critically explores the advance of science from the Ionians through Charles Darwin. Somewhat critical of Thales’ theories, even within the context of the ancient world. Contains a limited annotated bibliography of general works, but a more specific list of sources concludes each chapter. Includes several illustrations and a chronology of scientific discoveries and innovations.