DemocritusDemocritus (dɪˈmɒkrɪtəs, ; Δημόκριτος, Dēmókritos, meaning "chosen of the people"; 460 – 370 BC) was an Ancient Greek pre-Socratic philosopher from Abdera, primarily remembered today for his formulation of an atomic theory of the universe. None of his work has survived. Although many anecdotes about Democritus' life survive, their authenticity cannot be verified and modern scholars doubt their accuracy. Democritus was said to be born in the city of Abdera in Thrace, an Ionian colony of Teos.
UniverseThe universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787billion years ago, and the universe has been expanding ever since the Big Bang. While the spatial size of the entire universe is unknown, it is possible to measure the size of the observable universe, which is approximately 93 billion light-years in diameter at the present day.
ParmenidesParmenides of Elea (pɑːrˈmɛnɪdiːz...ˈɛliə; Παρμενίδης ὁ Ἐλεάτης; fl. late sixth or early fifth century BC) was a pre-Socratic Greek philosopher from Elea in Magna Graecia. Parmenides was born in the Greek colony of Elea, from a wealthy and illustrious family. His dates are uncertain; according to doxographer Diogenes Laërtius, he flourished just before 500 BC, which would put his year of birth near 540 BC, but in the dialogue Parmenides Plato has him visiting Athens at the age of 65, when Socrates was a young man, c.
PhilosophyPhilosophy (love of wisdom in ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, values, mind, and language. It is a rational and critical inquiry that reflects on its own methods and assumptions. Historically, many of the individual sciences, like physics and psychology, formed part of philosophy. But they are considered separate academic disciplines in the modern sense of the term.
Classical elementThe classical elements typically refer to earth, water, air, fire, and (later) aether which were proposed to explain the nature and complexity of all matter in terms of simpler substances. Ancient cultures in Greece, Tibet, and India had similar lists which sometimes referred, in local languages, to "air" as "wind" and the fifth element as "void". These different cultures and even individual philosophers had widely varying explanations concerning their attributes and how they related to observable phenomena as well as cosmology.
Air (classical element)Air or Wind is one of the four classical elements along with water, earth and fire in ancient Greek philosophy and in Western alchemy. According to Plato, it is associated with the octahedron; air is considered to be both hot and wet. The ancient Greeks used two words for air: aer meant the dim lower atmosphere, and aether meant the bright upper atmosphere above the clouds. Plato, for instance writes that "So it is with air: there is the brightest variety which we call aether, the muddiest which we call mist and darkness, and other kinds for which we have no name.
XenophanesXenophanes of Colophon (zəˈnɒfəniːz ; Ξενοφάνης ὁ Κολοφώνιος ksenophánɛːs ho kolophɔ̌ːnios; c. 570 – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer from Ionia who travelled throughout the Greek-speaking world in early Classical Antiquity. As a poet, Xenophanes was known for his critical style, writing poems that are considered among the first satires. He also composed elegiac couplets that criticised his society's traditional values of wealth, excesses, and athletic victories.
PythagorasPythagoras of Samos (Pythagóras ho Sámios, or simply Πυθαγόρας; Πυθαγόρης in Ionian Greek; 570-495 BC) was an ancient Ionian Greek philosopher, polymath and the eponymous founder of Pythagoreanism. His political and religious teachings were well known in Magna Graecia and influenced the philosophies of Plato, Aristotle, and, through them, the West in general. Knowledge of his life is clouded by legend, but he appears to have been the son of Mnesarchus, a gem-engraver on the island of Samos or the city of Tyre.
Ionian School (philosophy)The Ionian school of Pre-Socratic philosophy refers to Ancient Greek philosophers, or a school of thought, in Ionia in the 6th century B.C, the first in the Western tradition. The Ionian School included such thinkers as Thales, Anaximander, Anaximenes, Heraclitus, Anaxagoras, and Archelaus. This classification can be traced to the doxographer Sotion. The doxographer Diogenes Laërtius divides pre Socratic philosophy into the Ionian and Italian School.
NatureNature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans are part of nature, human activity is often understood as a separate category from other natural phenomena. The word nature is borrowed from the Old French nature and is derived from the Latin word natura, or "essential qualities, innate disposition", and in ancient times, literally meant "birth".
