Ancient Philosophy - Greek Era
Anaximander (c. 610 - c. 546 BC) was a pre-Socratic Greek philosopher who lived in Miletus, a city of Ionia; Milet in modern Turkey. He belonged to the Milesian school and learned the teachings of his master Thales. He succeeded Thales and became the second master of that school where he counted Anaximenes and arguably, Pythagoras amongst his pupils.
Little of his life and work is known today. According to available historical documents, he is the first philosopher known to have written down his studies, although only one fragment of his work remains. Fragmentary testimonies found in documents after his death provide a portrait of the man.
Anaximenes of Miletus (b. 585 BC - d. 528 BC) was an Archaic Greek Pre-Socratic philosopher active in the latter half of the 6th century BC.One of the three Milesian philosophers, he is identified as a younger friend or student of Anaximander.Anaximenes, like others in his school of thought, practiced material monism.This tendency to identify one specific underlying reality made up of a material thing constitutes the bulk of the contributions for which Anaximenes is most famed.
Pythagoras of Samos (b. about 570 - d. about 495 BC) was an Ionian Greek philosopher, mathematician, and founder of the religious movement called Pythagoreanism. Most of the information about Pythagoras was written down centuries after he lived, so very little reliable information is known about him. He was born on the island of Samos, and might have travelled widely in his youth, visiting Egypt and other places seeking knowledge. Around 530 BC, he moved to Croton, a Greek colony in southern Italy, and there set up a religious sect. His followers pursued the religious rites and practices developed by Pythagoras, and studied his philosophical theories. The society took an active role in the politics of Croton, but this eventually led to their downfall. The Pythagorean meeting-places were burned, and Pythagoras was forced to flee the city. He is said to have ended his days in Metapontum.
Pythagoras made influential contributions to philosophy and religious teaching in the late 6th century BC. He is often revered as a great mathematician, mystic and scientist, but he is best known for the Pythagorean theorem which bears his name. However, because legend and obfuscation cloud his work even more than that of the other pre-Socratic philosophers, one can give only a tentative account of his teachings, and some have questioned whether he contributed much to mathematics and natural philosophy. Many of the accomplishments credited to Pythagoras may actually have been accomplishments of his colleagues and successors. Whether or not his disciples believed that everything was related to mathematics and that numbers were the ultimate reality is unknown. It was said that he was the first man to call himself a philosopher, or lover of wisdom, and Pythagorean ideas exercised a marked influence on Plato, and through him, all of Western philosophy.
Xenophanes of Colophon (c.570 - c.475 BC) was a Greek philosopher, theologian, poet, and social and religious critic. Xenophanes lived a life of travel, having left Ionia at the age of 25 and continuing to travel throughout the Greek world for another 67 years. Some scholars say he lived in exile in Siciliy. Knowledge of his views comes from fragments of his poetry, surviving as quotations by later Greek writers. To judge from these, his elegiac and iambic poetry criticized and satirized a wide range of ideas, including Homer and Hesiod, the belief in the pantheon of anthropomorphic gods and the Greeks' veneration of athleticism. He is the earliest Greek poet who claims explicitly to be writing for future generations, creating "fame that will reach all of Greece, and never die while the Greek kind of songs survives."
Heraclitus of Ephesus (c. 535 - c. 475 BCE) was a pre-Socratic Greek philosopher, a native of the Greek city Ephesus, Ionia, on the coast of Asia Minor. He was of distinguished parentage. Little is known about his early life and education, but he regarded himself as self-taught and a pioneer of wisdom. From the lonely life he led, and still more from the riddling nature of his philosophy and his contempt for humankind in general, he was called "The Obscure" and the "Weeping Philosopher".
Heraclitus is famous for his insistence on ever-present change in the universe, as stated in the famous saying, "No man ever steps in the same river twice". He believed in the unity of opposites, stating that "the path up and down are one and the same", all existing entities being characterized by pairs of contrary properties. His cryptic utterance that "all entities come to be in accordance with this Logos" (literally, "word", "reason", or "account") has been the subject of numerous interpretations.
Parmenides of Elea (early 5th century BCE) was an ancient Greek philosopher born in Elea, a Greek city on the southern coast of Italy. He was the founder of the Eleatic school of philosophy. The single known work of Parmenides is a poem, On Nature, which has survived only in fragmentary form. In this poem, Parmenides describes two views of reality. In "the way of truth" (a part of the poem), he explains how reality (coined as "what-is") is one, change is impossible, and existence is timeless, uniform, necessary, and unchanging. In "the way of opinion," he explains the world of appearances, in which one's sensory faculties lead to conceptions which are false and deceitful. These ideas strongly influenced the whole of Western philosophy, perhaps most notably through its effect on Plato.
Anaxagoras ("lord of the assembly"; c. 500 - 428 BC) was a Pre-Socratic Greek philosopher. Born in Clazomenae in Asia Minor, Anaxagoras was the first philosopher to bring philosophy from Ionia to Athens. He attempted to give a scientific account of eclipses, meteors, rainbows, and the sun, which he described as a fiery mass larger than the Peloponnese. According to Diogenes Laertius and Plutarch he fled to Lampsacus due to a backlash against his pupil Pericles.
Anaxagoras is famous for introducing the cosmological concept of Nous (mind), as an ordering force. He regarded material substance as an infinite multitude of imperishable primary elements, referring all generation and disappearance to mixture and separation respectively.
Protagoras (ca. 490 BC - 420 BC) was a pre-Socratic Greek philosopher and is numbered as one of the sophists by Plato. In his dialogue Protagoras, Plato credits him with having invented the role of the professional sophist or teacher of virtue. He is also believed to have created a major controversy during ancient times through his statement that "man is the measure of all things". This idea was revolutionary for the time and contrasted with other philosophical doctrines that claimed the universe was based on something objective, outside the human influence.
Socrates (c. 469 BC - 399 BC) was a classical Greek Athenian philosopher. Credited as one of the founders of Western philosophy, he is an enigmatic figure known chiefly through the accounts of later classical writers, especially the writings of his students Plato and Xenophon, and the plays of his contemporary Aristophanes. Many would claim that Plato's dialogues are the most comprehensive accounts of Socrates to survive from antiquity.
Through his portrayal in Plato's dialogues, Socrates has become renowned for his contribution to the field of ethics, and it is this Platonic Socrates who also lends his name to the concepts of Socratic irony and the Socratic method, or elenchus. The latter remains a commonly used tool in a wide range of discussions, and is a type of pedagogy in which a series of questions are asked not only to draw individual answers, but also to encourage fundamental insight into the issue at hand. It is Plato's Socrates that also made important and lasting contributions to the fields of epistemology and logic, and the influence of his ideas and approach remains strong in providing a foundation for much western philosophy that followed.
Democritus (ca. 460 - ca. 370 BC) was an Ancient Greek philosopher born in Abdera, Thrace, Greece. He was an influential pre-Socratic philosopher and pupil of Leucippus, who formulated an atomic theory for the universe.
His exact contributions are difficult to disentangle from those of his mentor Leucippus, as they are often mentioned together in texts. Their speculation on atoms, taken from Leucippus, bears a passing and partial resemblance to the nineteenth-century understanding of atomic structure that has led some to regard Democritus as more of a scientist than other Greek philosophers; however their ideas rested on very different bases. Largely ignored in ancient Athens, Democritus was nevertheless well known to his fellow northern-born philosopher Aristotle. Plato is said to have disliked him so much that he wished all his books burned. Many consider Democritus to be the "father of modern science".
Antisthenes (c. 445 BCE - c. 365 BCE) was a Greek philosopher and a pupil of Socrates. Antisthenes first learned rhetoric under Gorgias before becoming an ardent disciple of Socrates. He adopted and developed the ethical side of Socrates' teachings, advocating an ascetic life lived in accordance with virtue. Later writers regarded him as the founder of Cynic philosophy.
Xenophon (c. 430 - 354 BC), son of Gryllus, of the deme Erchia of Athens, also known as Xenophon of Athens, was a Greek historian, soldier, mercenary, philosopher and a contemporary and admirer of Socrates. He is known for his writings on the history of his own times, the 4th century BC, preserving the sayings of Socrates, and descriptions of life in ancient Greece and the Persian Empire.
Plato (424/423 BC - 348/347 BC) was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the foundations of Western philosophy and science.
Aristotle (384 BC - 322 BC) was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology. Together with Plato and Socrates (Plato's teacher), Aristotle is one of the most important founding figures in Western philosophy. Aristotle's writings were the first to create a comprehensive system of Western philosophy, encompassing morality, aesthetics, logic, science, politics, and metaphysics.
Aristotle's views on the physical sciences profoundly shaped medieval scholarship, and their influence extended well into the Renaissance, although they were ultimately replaced by Newtonian physics. In the zoological sciences, some of his observations were confirmed to be accurate only in the 19th century. His works contain the earliest known formal study of logic, which was incorporated in the late 19th century into modern formal logic. In metaphysics, Aristotelianism had a profound influence on philosophical and theological thinking in the Islamic and Jewish traditions in the Middle Ages, and it continues to influence Christian theology, especially the scholastic tradition of the Catholic Church. Aristotle was well known among medieval Muslim intellectuals and revered as - "The First Teacher". His ethics, though always influential, gained renewed interest with the modern advent of virtue ethics. All aspects of Aristotle's philosophy continue to be the object of active academic study today. Though Aristotle wrote many elegant treatises and dialogues (Cicero described his literary style as "a river of gold"), it is thought that the majority of his writings are now lost and only about one-third of the original works have survived.
The main principle of Pyrrho's thought is expressed by the word acatalepsia, which connotes the ability to withhold assent from doctrines regarding the truth of things in their own nature; against every statement its contradiction may be advanced with equal justification. Secondly, it is necessary in view of this fact to preserve an attitude of intellectual suspense, or, as Timon expressed it, no assertion can be known to be better than another. Thirdly, Pyrrho applied these results to life in general, concluding that, since nothing can be known, the only proper attitude is ataraxia, "freedom from worry". ("By suspending judgment, by confining oneself to phenomena or objects as they appear, and by asserting nothing definite as to how they really are, one can escape the perplexities of life and attain an imperturbable peace of mind.").
The proper course of the sage, said Pyrrho, is to ask himself three questions. Firstly we must ask what things are and how they are constituted. Secondly, we ask how we are related to these things. Thirdly, we ask what ought to be our attitude towards them. Pyrrho's answer was that things are indistinguishable, unmeasurable, undecidable, and no more this than that, or both this and that and neither this nor that. He concluded that human senses neither transmit truths nor lie. Humanity cannot know the inner substance of things, only how things appear.
The impossibility of knowledge, even in regard to our own ignorance or doubt, should induce the wise person to withdraw into themselves, avoiding the stress and emotion which belong to the contest of vain imaginings. This theory of the impossibility of knowledge is the first and the most thorough exposition of noncognitivism in the history of thought. Its ethical implications may be compared with the ideal tranquility of the Stoics and the Epicureans.
Epicurus (341 BCE - 270 BCE) was an ancient Greek philosopher as well as the founder of the school of philosophy called Epicureanism. Only a few fragments and letters of Epicurus's 300 written works remain. Much of what is known about Epicurean philosophy derives from later followers and commentators.
For Epicurus, the purpose of philosophy was to attain the happy, tranquil life, characterized by ataraxia-peace and freedom from fear-and aponia-the absence of pain-and by living a self-sufficient life surrounded by friends. He taught that pleasure and pain are the measures of what is good and evil; death is the end of both body and soul and should therefore not be feared; the gods do not reward or punish humans; the universe is infinite and eternal; and events in the world are ultimately based on the motions and interactions of atoms moving in empty space.
Zeno of Citium (c. 334 BC - c. 262 BC) was a Greek thinker from Citium. Zeno was the founder of the Stoic school of philosophy, which he taught in Athens from about 300 BC. Based on the moral ideas of the Cynics, Stoicism laid great emphasis on goodness and peace of mind gained from living a life of Virtue in accordance with Nature. It proved very successful, and flourished as the dominant philosophy from the Hellenistic period through to the Roman era.
Euclid was a Greek mathematician, often referred to as the "Father of Geometry". He was active in Alexandria during the reign of Ptolemy I (323 - 283 BC). His Elements is one of the most influential works in the history of mathematics, serving as the main textbook for teaching mathematics (especially geometry) from the time of its publication until the late 19th or early 20th century.In the Elements, Euclid deduced the principles of what is now called Euclidean geometry from a small set of axioms. Euclid also wrote works on perspective, conic sections, spherical geometry, number theory and rigor.
Chrysippus of Soli (c. 279 BC - c. 206 BC) was a Greek Stoic philosopher. He was a native of Soli, Cilicia, but moved to Athens as a young man, where he became a pupil of Cleanthes in the Stoic school. When Cleanthes died, around 230 BC, Chrysippus became the third head of the school. A prolific writer, Chrysippus expanded the fundamental doctrines of Zeno of Citium, the founder of the school, which earned him the title of Second Founder of Stoicism.
Chrysippus excelled in logic, the theory of knowledge, ethics and physics. He created an original system of propositional logic in order to better understand the workings of the universe and role of humanity within it. He adhered to a deterministic view of fate, but nevertheless sought a role for personal freedom in thought and action. Ethics, he taught, depended on understanding the nature of the universe, and he taught a therapy of extirpating the unruly passions which depress and crush the soul. He initiated the success of Stoicism as one of the most influential philosophical movements for centuries in the Greek and Roman world.
Carneades (214/3-129/8 BC) was an Academic skeptic born in Cyrene. By the year 159 BC, he had started to refute all previous dogmatic doctrines, especially Stoicism, and even the Epicureans whom previous skeptics had spared. As head of the Academy, he was one of three philosophers sent to Rome in 155 BC where his lectures on the uncertainty of justice caused consternation among the leading politicians. He left no writings and many of his opinions are known only via his successor Clitomachus. He seems to have doubted the ability, not just of the senses but of reason too, in acquiring truth. His skepticism was, however, moderated by the belief that we can, nevertheless, ascertain probabilities of truth, to enable us to live and act correctly.