Philosopher (316 BC – 240 BC)

Arcesilaus is the second most important representative of the Skeptic School of Philosophy, founded by Pyrrhon. A student of Theophrastus, Arcesilaus is said to have doubted everything, similar to Descartes’ skepticism. None of his works on philosophy survive. As such, what we know about his philosophy is based on others’ accounts.

He studied geometry and astronomy before settling in Athens. After studying next to Theophrastus, he joined Plato’s Academy, where he studied philosophy next to Crantor, Crates and Polemon. He succeeded Crates as the sixth headmaster of the Academy, a position which he held for 25 years until his own death.

Our understanding of Arcesilaus’ skepticism is incomplete because his philosophy is survived only from brief reports by other writers and their opponents. Hence, each one gives their own interpretation of Arcesilaus’ philosophical views. Philosophers have interpreted his philosophy in three different ways: the Academic, the Practical and the Socratic interpretations.

Arcesilaus believed that we should not give a definite opinion on anything and that we should have a suspension of judgment – a term he named universal epoche (εποχή) – when we cannot distinguish between truth and falsehood. Nevertheless, he did not deny the performance of deeds, as our actions come from our will, not from our knowledge. Arcesilaus also held another doctrine called akatalepsia (ακαταληψία), according to which nothing can be known. He was highly critical of all philosophical movements, most notably against the Stoics.

Arcesilaus’ statements that one should not form beliefs and that nothing can be known have long bewildered philosophers, who have attempted to shed light to his way of thinking. Regardless, Arcesilaus made an important step in Academic Skepticism, as a skilled dialectitian following the Socratic Method, influencing important figures in philosophy.


  1. Brittain, Charles. Arcesilaus. Stanford Encyclopaedia of Philosophy. January 14, 2005. Web.
  2. Pleures, Konstantinos. Greek Philosophers. Hilektron Publications. Athens: 2014. Print.



Philosopher, Historian, Economist, General (c.430 BC – 354 BC)

Xenophon of Athens made a name of himself as a multifarious individual. He was a historian, an economist and a political writer, who continued Thucydides’ History of the Peloponnesian War. In addition to being a philosopher, Xenophon was an excellent general, who encompassed all the powers and values of Ancient Greece.

He was born in Athens during the Peloponnesian War. He was a student of Socrates. When the Athenians sentenced Socrates to death, Xenophon left Athens in disgust and settled in Sparta. He became a mercenary and served in the Army of the Ten Thousands, a part of King Cyrus’s army, as they ventured to Persia to dethrone Cyrus’ brother, Artaxerxes. Xenophon would later assume the leadership of this army and lead them to safety back to Asia Minor. Xenophon’s accounts are told in his book Anabasis, one of his greatest works written, which also accounts the Battle of Cunaxa.

Xenophon was a great admirer of Sparta. Upon his return to Greece, he continued serving the Spartans as a general. For his services, Sparta provided him with a private estate in Peloponnesus, where he lived for 23 years, writing his works. Xenophon was exiled from Athens for allying with the Spartans. However, as he proved that he was a military genius, his exile was revoked. Nevertheless, he never returned to Athens.

Xenophon wrote historical, “Socratic” and didactic treatises. Among his historical works are De Republica Lacaedemoniorum, a treatise on the political and social system of Sparta, its structure and its institutions, Agesilaus, a treatise on the life and work of King Agesilaus of Sparta, whom Xenophon considered an “ideal type of man and general”, Hellenica, a continuation of Thucydides’ major historical work The History of the Peloponnesian War, which covers the events of the war from 411 BC to 362 BC and Cyropaedia, a fictional biography of Cyrus the Great, King of Persia.

His “Socratic dialogues” are works named after Socrates, who serves as the central figure of the dialogue. In Apology of Socrates, Socrates defends himself in front of the jury by demonstrating his virtue and wisdom. Memorabilia features dialogues and conversations with Socrates and the ethical influence has on others. In this category also belong two of his works Oeconomicus and Symposion, a conversation with Socrates involving home economics and a dialogue on love respectively.

Xenophon’s didactic treatises provide valuable information on the correct treatment and use of horses, instructions on strategic and tactical matters of war, as well as solutions to the remediation of Athens’ economy.

A philosopher with high educational background, Xenophon’s philosophy was largely influenced by Socrates. As a political philosopher, he endorsed the strict political system of Sparta, the goal of which was set years ago by Lycurgus. As a moral philosopher, Xenophon highlighted the importance of discipline, moderation and self-control. For him, hard work is a virtue, even for a King, as presented in Oeconomicus, where Cyrus the Great is said to be taking care of his own garden regularly.

As early from the Alexandrian era, Xenophon was highly valued by historians and philologists, who placed him among Herodotus and Thucydides. His legacy continued unchanged during the Roman Empire. In the Renaissance, European scholars used his works for didactic purposes: the Memorabilia to teach about Socrates and his philosophy, Agesilaus for the virtues of an ideal leader, Anabasis for the discipline, initiative and wise decision-making, Cyropaedia for the importance of education, and the Hellenica as the most valuable source for the history of Greece during that era.


  1. Βολωνάκης, Κ. Ιωάννης. Της Αρχαίας Ελλάδος οι Μεγάλοι Ηγέται. Γεοργιάδης: Αθήναι, 1997. Print.
  2. Browning, Eve A. Xenophon. Internet Encyclopaedia of Philosophy. Web.
  3. Διαλησμά, Δρουκόπουλος, Κουτρουμπέλη, Χρυσαφής. Αρχαίοι Έλληνες Ιστοριογράφοι. Οργανισμός Εκδόσεως Σχολικών Βιβλίων. Διδακτικά Σχολικά Βιβλία. Print.

Conon of Samos

Astronomer, Mathematician, Geographer (c.280 BC – c.220 BC)

Conon of Samos is renowned for his contributions in astronomy. He was a contemporary and close friend of Archimedes, with whom he exchanged mathematical ideas. He lived in Alexandria and worked in the court of Ptolemy III Euergetes, with whom he was also a close friend.

Conon discovered the constellation of Coma Berenices, found between the constellations of Virgo, Leo and Bootes. He named it poetically after the rich hair of Queen Berenice II, wife of Ptolemy III Euergetes.

His works are numerous, but sadly the majority of them have been lost. Among them, De Astrologia, a treatise consisting of 7 books dedicated to Ptolemy III Euergetes. It contained Conon’s own astronomical observations on solar eclipses. This treatise was used by Hipparchus. Another one of his works was Parapegmata, a diary containing meteorological forecasts and information on the risings and settings of stars. His data was a result of meticulous observations he had conducted in Magna Graecia.

In addition to astronomy and geography, Conon was a skilled mathematician. His work on conic sections, which also does not survive, formed the basis of Apollonius of Perga’s 4th book of Conics. It is also believed, based on accounts from Pappus of Alexandria, that Conon was the original inventor of the Archimedean spiral.

At his time, Conon was recognized as a prestigious mathematician. Callimachus wrote a poem entitled Coma Berenices, which writes about Conon that he “discerned all the lights of the vast universe and disclosed the risings and settings of the stars, how the fiery brightness of the sun is darkened and how the stars retreat at fixed times”.


  1. Georgakopoulos, Konstantinos. Ancient Greek Scientists. Georgiades: Athens, 1995. Print.
  2. J.J. O’Connor, E.F. Robertson. Conon of Samos. University of St. Andrews. Web.
Conon of Samos

Heraclides of Pontus

Philosopher, Astronomer (4th century BC)

Heraclides descended from a wealthy family from Heraclea Pontica. He was a philosopher and astronomer, the first to propose a mixed geo-heliocentric system of the universe. His vast bibliography, which unfortunately does not survive today, spanned the fields of physics, astronomy, metaphysics and meteorology.

He studied in the Academy of Athens where he became one of Plato’s students and later a student of Aristotle in the Lyceum. In the Academy he befriended Speusippus, the successor of the school. Upon Speusippus’ death, Heraclides was one of the candidates for headmaster of the Academy, but lost to Xenocrates. He returned to his hometown Heraclea where he founded his own philosophic school. Heraclides possessed profound knowledge on Pythagorean philosophy and was a proponent of Demorcitus’ theory of the atom.

Heraclides was active primarily in astronomy. He proposed the mixed helio-geocentric model of the cosmos according to which the sun, the moon and the planets of the solar system rotate around the Earth, except from Venus and Mercury, who orbit the Sun. Heraclides also postulated that the Earth completes a rotation around its axis in 24 hours. He was the first philosopher to hold such a belief. This model proposed by the philosopher is believed to have served as the basis for the astronomical model of Tycho Brahe.

Heraclides was a prolific writer. Like most of his contemporaries, he wrote a book On Nature, a treatise on physics. Furthermore, he wrote the philosophical books On the Pythagoreans, On Hades and on Uranus, On Findings and Zoroaster, books on the philosophy of physics, literary critiques, books on mysticism and books on theurgy or medicine. As a Platonic philosopher, Heraclides endorsed the concept of the immortality of the soul as well as reincarnation. According to him, the soul is made of light (φῶς) and aether (αἰθέρα). It originates from the Galaxy.


  1. Georgakopoulos, Konstantinos. Ancient Greek Scientists. Georgiades: Athens, 1995. Print.
  2. J.G. Toomer. Heraclides Ponticus. Web.
  3. Κάλφας, Βασίλης. Ηρακλείδης Ποντικός. Η Εγκυκλοπαίδεια του Πλάτωνα. Web.
Heraclides of Pontus



Painter (c.370 BC – c.306 BC)

The greatest painter of antiquity, widely considered as the equivalent of Pheidias in painting, Apelles succeeded in depicting the perfect, with extraordinary realism, colours and symbolism, while excluding all hyperboles. Many of today’s most famous paintings are in actuality recreations of Apelles’ paintings.

His hometown was either from the island of Kos from Colophon. He studied art for 12 years in the Sicyon Art School next to multiple renowned painters of his time. From there he went to Macedonia, where he became acquainted with Alexander the Great. Apelles, together with Lysippus worked in the royal Macedonian court. Alexander also took him with him during his expedition in Asia. It is said that Alexander allowed only Apelles to portray him in paintings because of his remarkable talent.

Apelles was renowned for the richness of his colours. He created his own revolutionary method which consisted of mixing pigments out of plant extracts and burning of ivory, transfusing an unparalleled vividness and expressivity in his paintings. His art was praised by Pliny for its ingenuity and innate grace (ingenium et gratia). He pioneered the use of symbolism in paintings, being the first to portray allegories and personifications such as ignorance, contempt, sycophancy, justice and truth. He was hailed as one of the greatest painters by his contemporaries as well as being a perfectionist. Pliny, from whom we get a significant amount of information on Apelles, said that it was Apelles who surpassed all the painters that preceded him and all those that followed.

Although most of his paintings do not survive, there have been descriptions of them as well as faithful replicas. One of these is the mural in the house of Vetii in Pompeii depicting Alexander the Great battling against Darius in the Battle of Issus. It is based on the original painting by Apelles of Alexander wielding a thunderbolt in the image of Zeus found in the Temple of Artemis in Ephesus. Another mural found in Pompeii, that depicts the birth of Venus is based on Apelles’ Aphrodite Anadyomene (Venus Rising from the Sea). This painting served as an inspiration to a multitude of paintings during the Renaissance that revolved around the birth of Venus, including Botticelli’s famous The Birth of Venus. In a similar manner, Apelles’ Calumny became the basis for Zuccaro’s and Botticelli’s Calumny of Apelles. Other paintings include a portrait of Artemis surrounded by maidens based on an episode from Homer’s Odyssey, the Sacrifice in Cos as well as many other portraits of Gods and mortals alike.

Apelles’ legacy endured strongly during the Renaissance, which was a spiritual child of Hellenism. Numerous painters followed in his footsteps in an attempt to emulate him. The most notable example is Botticelli, who himself believed that he was the reincarnation of Apelles. It can be concluded that Apelles’ impact on the painters of the Renaissance was undoubtedly enormous, serving as their quintessence. He is depicted in Raphael’s The School of Athens, Willem van Haecht’s Alexander the Great Visits the Studio of Apelles and Apelles Painting Campaspe, Charles Meynier’s Alexander the Great Gives Campaspe to Apelles, Charles Beranger’s The Hemicycle and in Paul Delaroche’s The Hemicycle, where he is sitting on a throne in the center of an amphitheatre, in between Ictinus and Pheidias. Apelles is among the many great Greeks offering his tribute to Homer in Ingres’ The Apotheosis of Homer. His reputation as the one who perfected the art of painting has well withstood the test of time.


  1. Απελλής. Ἰδρυμα Μείζωνος Ελληνισμού. Web.
  2. Bompart, Malvina. Απελλής, ο διασημότερος ζωγράφος της αρχαιότητας ,πρότυπο των μετέπειτα γενεών. ΑΡΧΑΙΟΓΝΩΜΩΝ. Web. June 7, 2015.
  3. hoakley. The Story in Paintings: Apelles, the Oldest Master of All. The Eclectic Light Company. Web. June 9, 2016.


Mathematician (c.200 BC – c.140 BC)

Zenodorus of Paiania was a mathematician, founder of the theory of isoperimetric figures in geometry. He lived during the end of the 3rd century BC and taught in the Museum of Alexandria, the greatest spiritual center of humanity at the time.

Zenodorus was active a few years after Archimedes’ death, whose work “Measurement of the Circle” he accounts. He came from a wealthy family in Athens. It is believed that he was also an Epicurean philosopher. He was a close friend of Apollonius of Perga and Diocles of Alexandria.

Zenodorus first introduced the concept of the isoperimetric figures in geometry. His work is survived in his treatise On isoperimetric figures, excerpts of which are contained in the works of Pappus of Alexandria, Proclus and Theon. Zenodorus proved that of all the solid figures with equal surfaces, the sphere is the greatest, that the equiangular and equilateral polygon is the greatest in area out of all the polygons with the same number of sides and equal perimeter and that the circle is greater than any regular polygon of equal contour. Moreover, Zenodorus proved that the polygon with the most angles has the greatest area than all regular polygons with the same perimeter.

It is not known if Zenodorus wrote any other treatises, as nothing else has survived of his work. Nevertheless, his influence in geometry is evident from the fact that he is mentioned by numerous mathematicians such as Diocles, Theon, Proclus, Eutocius, Simplicius as well as multiple Arabian mathematicians. Pappus of Alexandria, who basically compares the area or volume of different geometric shapes with the same perimeter in the 5th book of his treatise “Mathematical Synagogue”, expands Zenodorus’ work on the isometric or isoperimetric figures.

Not surprisingly, Zenodorus’ work had and important impact on the mathematicians of the 18th, 19th and 20th centuries. His work opened the way for the discovery of the area of mathematics known as calculus of variations. It is worth mentioning that great mathematical minds of history acknowledge Zenodorus as an important figure in the advancement of mathematics. In one of his letters to Leonhard Euler, Joseph – Louis Langange characterizes Zenodorus as “the first teacher (τὸν πρῶτον διδάξαντα)” while Constantine Caratheodory considered him as the Father of the Calculus of Variations.


  1. Georgakopoulos, Konstantinos. Ancient Greek Scientists. Georgiades: Athens, 1995. Print.
  2. Ζηνόδωρος ο Παιανεύς Ένας Μεγάλος Μαθηματικός. Excerpt from the book Ζηνόδωρος ο Παιανεύς ( Ένας Μεγάλος Μαθηματικός). Αίθρα. Αθήνα, 2011. by Evangelos Spandagos. Web.



Philosopher, Mathematician, Physicist, Astronomer, Biologist, Writer, Scholar, Rhetorician, Statesman, Psychologist, Naturalist (384 BC – 322 BC)

Aristotle is one of the most polymath philosophers to have ever come to this world. He has given humanity an immortal consignment, which extends to almost every science and art. He is the founder of the Peripatetic School of Philosophy, which gave birth to Aristotelianism, the philosophy which defines Aristotle. While there have been conflicts throughout the ages between Aristotle’s and Plato’s philosophy, Aristotle does not decline much from Plato’s philosophy. He does not ascend to Plato’s Theory of Ideas, but is most powerful at the level of humanity’s physical field.

He was born in Stagira. At age 17 he went to study philosophy in the Academy of Athens following a pronouncement from the Oracle of Delphi. There he became a student of Plato for almost 20 years. He also took lessons on rhetoric from Isocrates’ school. Following Plato’s death, Aristotle was nominated for successor of the Academy but the position was ultimately taken by Speusippus. Aristotle left for Assos, where he remained for 3 years until he was invited to Mytilene by Theophrastus to work as a teacher. Following an invitation from Philip II of Macedon, Aristotle became a tutor of Alexander the Great for 6 years. He then returned to Athens and founded the Lyceum. It was the start of Aristotelianism.

The Lyceum was founded with the financial aid of Alexander the Great. Aristotle built the first major library of the school, which would become the paradigm of the Library of Alexandria and accumulated important works on natural sciences. The Lyceum was where Aristotle taught his philosophy, which covered a huge spectrum of sciences.

Aristotle was not just a philosopher. He was a scientist, a homo universalis who individualized each science from philosophy and gave it its own standpoint. His attributed works are estimated to have been 400, 142 of which survive. He wrote treatises on philosophy, metaphysics, logic, mathematics, physics, biology, zoology, phytology, politics, ethics, psychology, rhetoric and many more.

According to Aristotle, it is in man’s nature to incline toward knowledge. Science is the main tool by which man achieves knowledge. It differs from art in the sense that science is concerned with knowledge. Its goal is to unveil the unchangeable laws of the universe. Aristotle defined wisdom as the highest perfection of science. It is the knowledge of the primordial causes and principles of the being, the inalterable laws that define the stable nature of the being. To the philosopher, wisdom is achieved when the characteristics of science are raised to their highest possible level. Wisdom (σοφία) is only God’s privilege. If man cannot attain wisdom in its fullness, then he can strive to achieve it by becoming a friend of wisdom, a philosopher (φιλόσοφος). Hence, philosophy is the struggle for wisdom. This struggle equilibrates man with God. Philosophy is man’s ultimate mission and it is in accordance to his nature. It liberates man from his double ignorance. Philosophy, therefore, is only for the free people.

For Aristotle, every science is philosophy. For this reason, he uses the terms science and philosophy interchangeably. Every science and philosophy must be a logos on beings to be worthy of its name. One of his greatest achievements was that he defined how research is conducted to prove a thesis in science. Aristotle’s analysis of the method that sciences use to prove things is the most perfect in scientific thought. For this reason, he is credited as the Father of the methodology of science. He taxonomized sciences into three types: theoretical, practical and poetic. He became the founder of the history of philosophy and the history of sciences as a discipline. Mythology, according to the philosopher himself, is part of philosophy.

Even though Aristotle did not compile detailed studies on mathematics, he was involved in the methodological syntaxis of the mathematical science. In mathematics, he studied the infinite and the continuous function in an innovative way. He also studied astronomy, since it is connected with philosophical cosmogony. His treatise On the Heavens, consisting of 4 books, is an ecthesis of astronomical theories and phenomena. He describes the universe, the planets of the solar system, the shape of the Earth, the stars, geographic and meteorological data, including the theory of chemical change, on comets, meteorites and metals. Some of these were used by Greek Christopher Colombus to travel to the Americas.

Physics, which is the study of nature, was one of Aristotle’s most beloved sciences. Aristotle’s Physics, consisting of 8 books in total, contains his entire works on physics. He dealt with the general method of science and the analytical method of research, provided definitions on nature and a distinction between physics and philosophy. He did extensive research on fundamental notions of kinetics and mechanics such as inertia, the types of movement, circular motion, the relativity of movement, change of matter, dynamic and kinetic energy, time and space relativity, relationship between infinity and the universe, time as a measure, flow of time, on void, matter and laws of gravity. Aristotle also deals with thermodynamics and sets the foundations of modern statistical science. His conclusions are based on mathematical analysis and experiments.

Aristotle is widely acknowledged as the Father of Biology, the one who established biology as a science. He also compiled studies on comparative anatomy, physiology, embryology, zoology and phytology. In his books he mentions over 500 species of animals and devises a system of animal taxonomy. His studies feature remarkable details on the organ function of animals, their movement, their reproduction, their behaviour as well as their inheritance. He studied the phenomena of life and rightly considered that the heart is the center of the soul. It is worth noting that Aristotle founded the first botanical garden in Athens, featuring a myriad of specimens from Europe and Asia, brought to him by Alexander the Great.

One of his greatest works are in the field of metaphysics, so called because they were written after his treatise on physics and nature (Μετὰ τὰ Φυσικά). Metaphysics, of which Aristotle is the founder, is the science of ontology. It did not have the meaning it has today. Aristotle calls his newly established philosophy as the First Philosophy (Πρώτη Φιλοσοφία). Metaphysics or Ontology is the study of ontologic reality, the fundamental principles upon which all sciences are based. It aims to uncover the common characteristics of all beings and to delve into the primordial principles that create the ontologic reality. His 12 books on metaphysics contain a critique on the theory of numbers as well as detailed studies on various topics that today pertain to physics, including energy, movement, matter and heat. Furthermore, it contains mathematical topics on proportionality, symmetry and mathematical axioms.

Aristotle is the most eminent philosopher of ethics, the principle founder of values. In his books Eudemian Ethics, Magna Moralia and Nichomachean Ethics, the latter being his magnum opus as depicted in Raphael’s The School of Athens, the philosopher defines virtue and categorizes it into intellectual and ethical virtues. Ethical virtues concern the emotions and actions of man. They are acquired by means of ethos. They are the mean of the two extreme states that are found on the opposite side, one being excess and the other deficiency. The ethical virtues form a 90 degree angle with both these extreme states. They are twelve in number. Intellectual virtues are acquired by means of learning. They are the virtues of logic and guide man’s emotions and instincts. Aristotle’s theory of ethics, in conjunction with Plato’s works on virtues, is the ultimate guide for achieving a healthful spiritual life.

Aristotle founded yet another philosophical science: Logic, which is one of Aristotle’s greatest contributions to humanity. He was extensively involved in rhetoric, poetry and psychology as well, compiling numerous treatises on the definition and types of souls, psychic characteristics and functions, boulisis and free will. Furthermore, Aristotle expanded significantly epistemology, the branch of philosophy that deals with the validity of science. All of his works are original, innovative and groundbreaking. They are products of Greek Meditation (ΔΙΑ-Λογισμοῦ).

Aristotle remains to this day one of the most prolific and influential philosophers in world history. His massive work evidently shows how much Aristotle was intrigued on issues that concern humanity today. Without his contribution, science would not have existed. International philosophy and scientific nomenclature uses words first defined by Aristotle, such as the word “dynamic” in economics, the words “matter” and “energy” in physics, and the word “continuity” in mathematics. It is impossible to count down all the philosophers that Aristotle has influenced over the millennia. It is worth of mention that Descartes’ quote “I think, therefore I am” is taken directly from Aristotle’s words, who said “When someone has the sensation of himself or someone else’s in continuous time, then it is impossible to not have conscious that he exists”. His ethics are an everlasting inheritance to all mankind. Their goal is for man to attain virtue, which is a prerequisite for a healthy soul. It is thanks to intellectual giants like Aristotle that Greece has held the reins of spiritual leadership of humanity.


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  3. Georgakopoulos, Konstantinos. Ancient Greek Scientists. Georgiades: Athens, 1995. Print.
  4. Pleures, Konstantinos. Greek Philosophers. Hilektron Publications: Athens, 2013. Print.
  5. Stokes, Philip. Philosophy: 100 Essential Thinkers. Phytrakis: Athens, 2002. Print.