Historians in the 19th century invented the word “Neoplatonism” which applied to the tradition of Plato. The first Neoplatonist was Plotinus (c. 204–205 AD to 270 AD) in Hellenistic Roman Egypt. His writings Enneads have inspired centuries of Pagan, Jewish, Christian, Gnostic, and Islamic metaphysicians and mystics.
The atomic theory was applied in everyday living by Epicurus (341 BC–270 BC), who was born 7 years after the death of Plato on the island Samos to Athenian parents. He turned against the Platonism of his day and established his own school, known as “the Garden’, in Athens. His purpose of philosophy was to attain the happy, tranquil life, characterised by ataraxia (peace and freedom from fear) and aponia (the absence of pain) and by living a self-sufficient life surrounded by friends. He openly allowed women to join the school as a matter of policy. Epicurus and his followers were known for eating simple meals and discussing a wide range of philosophical subjects.
But, most knowledge of his teachings did not come from Greek originals but from the Latin written later by the Roman poet Titus Lucretius Carus or commonly Lucretius, the biographer Diogenes Laërtius, the statesman Cicero, and the philosophers Philodemus and Sextus Empiricus. He taught that death is the end of both the body and the soul and therefore should not be feared. Likewise, Epicurus taught that the gods, though they do exist, have no involvement in human affairs and do not punish or reward people for their actions. Nonetheless, he maintained that people should still behave ethically, not because of the ‘goodness’ mentioned by Plato but because of the burden of guilt which prevents them from attaining ataraxia.
Though popular, Epicurean teachings, pursuit of happiness, were controversial from the beginning in Athens which was the city of Plato. Epicureanism reached the height of its popularity during the late years of the Western Roman Republic, before declining as the rival school of Stoicism grew in popularity at its expense. It finally died out in late antiquity in the wake of early Christianity after Justinian’s edict of 529 AD. Epicurus himself was popularly, though inaccurately, remembered throughout the Middle Ages as a patron of drunkards, whoremongers, and gluttons.
Of course, there were many philosophers in the first classical period who influenced the atomic theory and Plato’s universe. The first person who thought deeply and deviated from the use of mythology to explain the world and the universe was Thales (624–623 BC to 548–545 BC) in the city state of Miletus in the ancient Greek Ionia. He is recognised as the first individual known to have entertained and engaged in scientific philosophy in Western civilisation, or more impressively the first since achieving cognitive faculty. He was one of the Seven Sages of Greece. The other Sages were politicians, Pittacus of Lesvos, Bias of Priene, Solon of Athens, Cleobulus of Lindos, Periander of Corinth, and Chilon of Sparta (Some cite Myson of Chenae and philosopher Anacharsis of Scythia, instead of Cleobulus and Periander). Thales was also a politician but is known better as the founder of the Ionian School. He proclaimed that the originating principle of nature and the nature of matter was a single material substance: water. Anaximander (610 BC–546 BC) succeeded Thales and became the second master of the Ionian School. Arguably, Pythagoras was one among his pupils. As mentioned before, Anaximander defined the word arche and is considered to be an early proponent of science and tried to observe and explain different aspects of the universe, with a particular interest in its origins, claiming that nature is ruled by laws.
Another ancient Ionian Greek philosopher who influenced philosophers of later times was Pythagoras who was the eponymous founder of Pythagoreanism. His political and religious teachings were well known in Magna Graecia and influenced Plato, Aristotle, and through them Western philosophy. Pythagoras was credited with many mathematical and scientific discoveries, including the Pythagoras theorem, Pythagorean tuning, and the five regular solids, which were admired by Plato. It was said that he was the first man to call himself a philosopher (‘lover of wisdom’). Pythagorean ideas on mathematical perfection also impacted ancient Greek art. Pythagoras continued to be regarded as a great philosopher throughout the Middle Ages and his philosophy had a major impact on scientists such as Nicolaus Copernicus, Johannes Kepler, and Isaac Newton.
Diogenes Laërtius (3rd century AD) states that Pythagoras “did not indulge in the pleasures of love” and that he cautioned others to only have sex “whenever you are willing to be weaker than yourself”.
Parmenides and Zeno were born in Elea (560 BC–510 BC). Parmenides has been considered the founder of metaphysics or ontology and has influenced the whole history of Western philosophy. He was the founder of the Eleatic school of philosophy, which also included Zeno and Melissus of Samos. Zeno’s paradox was perhaps the first example of a method of proof called reductio ad absurdum, literally meaning to reduce to the absurd. Zeno’s paradoxes of motion were to defend Parmenides’ view. The single known work by Parmenides is a poem, On Nature, only fragments of which survive, containing the first sustained argument in the history of philosophy. In it, Parmenides prescribes two views of reality. In “the way of truth” (a part of the poem), he explains how all reality is one, change is impossible, and existence is timeless, uniform, and necessary. In the way of opinion, Parmenides explains the world of appearances, in which one’s sensory faculties lead to conceptions which are false and deceitful, yet he does offer a cosmology. Parmenides’ philosophy has been explained with the slogan “whatever is is, and what is not cannot be”. He is also credited with the phrase ex nihilo nihilo fit (out of nothing, nothing comes), commenting on Dẽmiourgos’ creation.
Before Democritus, Heraclitus (535 BC–475 BC) in Ephesus talked about the world in On Nature but he was uncertain where to place some words. So, he is nicknamed “The Obscure” or “The Riddler”. In Rhetoric, Aristotle described his style, “It is difficult to punctuate Heraclitus’ writings because it is unclear whether a word goes with what follows or with what precedes it. E.g. at the very beginning of his treatise, where he says: Of this account which holds forever men prove uncomprehending, it is unclear which ‘forever’ goes with.” He was author of On Nature which was dedicated to the great temple of Artemis, one of the Seven Wonders of the Ancient World. In Lives of the Philosophers, Diogenes Laërtius wrote, “They say that Euripides gave [Sokrates] a copy of Heraclitus’ book and asked him what he thought of it. He replied: ‘What I understand is splendid; and I think that what I don’t understand is so too — but it would take a Delian diver to get to the bottom of it.”’ Hippolytus presents a summary of Heraclitus’ main ideas in Refutation of All Heresies, “Heraclitus says that the universe is divisible and indivisible, generated and ungenerated, mortal and immortal, Word and Eternity, Father and Son, God and Justice.”
In Commentary on the Physics, Simplicius writes the following:
“In the first book of the Physics, Anaxagoras says that uniform stuffs, infinite in quantity, separate off from a single mixture, all things being present in all and each being characterized by what predominates. He makes this clear in the first book of the Physics at the beginning of which he says: Together were all things, infinite in quantity and in smallness. . .”
Here, Anaxagoras (510 BC–428 BC), born in Clazomenae and brought up in Athens, described the world as a mixture of primary imperishable ingredients, where material variation was never caused by an absolute presence of a particular ingredient, but rather by its relative preponderance over the other ingredients; in his words, “each one is ... most manifestly those things of which there are the most in it”. It is very similar to our understanding of chemical elements by Mendeleev’s table. But, he differs from Democritus’ atoms in introducing the concept of Nous (Cosmic Mind) as an ordering force, which moved and separated from the original mixture, which was homogeneous, or nearly so. He, being two generations before Democritus, might have influenced him. One generation before Democritus, Empedocles (490 BC–430 BC), a citizen of Akragas in Sicily, held the view that the four elements (fire, earth, breath, and rain written in Lucretius’ poem De Rerum Natura6) were those unchangeable fundamental realities. Plato had four elements, exactly the same as Empedocles’, changing breath to air and rain to water.