LeucippusLeucippus (luːˈsɪpəs; Λεύκιππος, Leúkippos; fl. 5th century BCE) was a pre-Socratic Greek philosopher who has been credited as the first philosopher to develop a theory of atomism. Leucippus' reputation, even in antiquity, was obscured by the reputation of his much more famous pupil, Democritus, who is also credited with the first development of atomic theory. Few details about Leucippus' life are known, and even his historical existence has on occasion been questioned.
MetaphysicsMetaphysics is the branch of philosophy that studies the fundamental nature of reality. This includes the first principles of: being or existence, identity, change, space and time, cause and effect, necessity, actuality, and possibility. Metaphysics is considered one of the four main branches of philosophy, along with epistemology, logic, and ethics. It includes questions about the nature of consciousness and the relationship between mind and matter, between substance and attribute, and between potentiality and actuality.
PhysicsPhysics is the natural science of matter, involving the study of matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. A scientist who specializes in the field of physics is called a physicist. Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest.
Zeno of EleaZeno of Elea (ˈziːnoʊ...ˈɛliə; Ζήνων ὁ Ἐλεᾱ́της; 495-430 BC) was a pre-Socratic Greek philosopher of Magna Graecia (southern Italy) and a member of the Eleatic School founded by Parmenides. Plato and Aristotle called him the inventor of the dialectic. He is best known for his paradoxes. Little is known for certain about Zeno's life. The primary source of biographical information about Zeno is Plato's dialogue Parmenides, which recounts a fictionalized account of a visit that Zeno and Parmenides made to Ancient Athens in 450 BC, at a time when Parmenides is "about 65", Zeno is "nearly 40", and Socrates is "a very young man".
Academic skepticismAcademic skepticism refers to the skeptical period of the Academy dating from around 266 BCE, when Arcesilaus became scholarch, until around 90 BCE, when Antiochus of Ascalon rejected skepticism, although individual philosophers, such as Favorinus and his teacher Plutarch, continued to defend skepticism after this date. Unlike the existing school of skepticism, the Pyrrhonists, they maintained that knowledge of things is impossible. Ideas or notions are never true; nevertheless, there are degrees of plausibility, and hence degrees of belief, which allow one to act.
LucretiusTitus Lucretius Carus (ˈtaɪtəs_luːˈkriːʃəs , ˈtɪtʊz lʊˈkreːti.ʊs ˈkaːrʊs; 99 – 55 BC) was a Roman poet and philosopher. His only known work is the philosophical poem De rerum natura, a didactic work about the tenets and philosophy of Epicureanism, and which usually is translated into English as On the Nature of Things—and somewhat less often as On the Nature of the Universe. Lucretius has been credited with originating the concept of the three-age system that was formalised in 1836 by C. J. Thomsen.
EleaticsThe Eleatics were a group of pre-Socratic philosophers and school of thought in the 5th century BC centered around the ancient Greek colony of Elea (Ἐλέα), located in present-day Campania in southern Italy, then known as Magna Graecia. The primary philosophers who are associated with the Eleatic doctrines are Parmenides, Zeno of Elea, and Melissus of Samos, although other Italian philosophers such as Xenophanes of Colophon and Empedocles have also sometimes been classified as members of this movement.
TheophrastusTheophrastus (ˌθiː.əˈfræstəs; ; 371 - 287 BC) was a Greek philosopher and the successor to Aristotle in the Peripatetic school. He was a native of Eresos in Lesbos. His given name was Τύρταμος (); his nickname Θεόφραστος () was given by Aristotle, his teacher, for his "divine style of expression". He came to Athens at a young age and initially studied in Plato's school. After Plato's death, he attached himself to Aristotle who took to Theophrastus in his writings. When Aristotle fled Athens, Theophrastus took over as head of the Lyceum.
Kaṇāda (philosopher)Kaṇāda (कणाद), also known as Ulūka, Kashyapa, Kaṇabhaksha, Kaṇabhuj was an ancient Indian natural scientist and philosopher who founded the Vaisheshika school of Indian philosophy that also represents the earliest Indian physics. Estimated to have lived sometime between 6th century to 2nd century BCE, little is known about his life. His traditional name "Kaṇāda" means "atom eater", and he is known for developing the foundations of an atomistic approach to physics and philosophy in the Sanskrit text Vaiśeṣika Sūtra.
NausiphanesNausiphanes (Ναυσιφάνης; lived c. 325 BC) was an ancient Greek atomist philosopher from Teos. Nausiphanes reportedly had a large number of pupils, and was particularly famous as a rhetorician. He argued that the study of natural philosophy (physics) was the best foundation for studying rhetoric or politics, which is attacked in a surviving work of Philodemus, On Rhetoric. Furthermore, Nausiphanes was an adherent of Democritus's sceptical side and deemed human judgment as being no more than a realignment of atoms in the mind.
