Ancient Roman philosophy in the context of "Natural law"

Ancient Greek philosophy arose in the 6th century BC. Philosophy was used to make sense of the world using reason. It dealt with a wide variety of subjects, including astronomy, epistemology, mathematics, political philosophy, ethics, metaphysics, ontology, logic, biology, rhetoric and aesthetics. Greek philosophy continued throughout the Hellenistic period and later evolved into Roman philosophy.

Greek philosophy has influenced much of Western culture since its inception, and can be found in many aspects of public education. Alfred North Whitehead once claimed: "The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato". Clear, unbroken lines of influence lead from ancient Greek and Hellenistic philosophers to Roman philosophy, early Islamic philosophy, medieval scholasticism, the European Renaissance and the Age of Enlightenment.

Stoicism is an ancient Greek and then Roman philosophy of the Hellenistic and Roman Imperial periods. The Stoics believed that the universe operated according to reason, or logos, providing a unified account of the world, constructed from ideals of rational discourse, monistic physics, and naturalistic ethics. These three ideals constitute virtue, which is necessary for the Stoic goal of 'living a well-reasoned life'.

Stoic logic focuses on highly intentional reasoning through propositions, arguments, and the differentiation between truth and falsehood. Philosophical discourse is paramount in Stoicism, including the view that the mind is in rational dialogue with itself. Stoic ethics centers on virtue as the highest good, cultivating emotional self-control, a calm problem-solving state of mind, and rational judgment to attain lifelong flourishing (eudaimonia). At the same time, passions, anxieties, and insecurities are viewed as misguided reactions that ought to be controlled through self-disciplined practice. Of all the schools of ancient Western philosophy, Stoicism made the greatest claim to being utterly systematic.

Titus Lucretius Carus (/ˈtaɪtəs luːˈkriːʃəs/ TY-təs loo-KREE-shəs; Latin: [ˈtitus luˈkreːti.us ˈkaːrus]; c. 99 – October 15, 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, which usually is translated into English as On the Nature of Things—and somewhat less often as On the Nature of the Universe. Very little is known about Lucretius's life; the only certainty is that he was either a friend or client of Gaius Memmius, to whom the poem was addressed and dedicated. De rerum natura was a considerable influence on the Augustan poets, particularly Virgil (in his Aeneid and Georgics, and to a lesser extent on the Eclogues) and Horace. The work was almost lost during the Middle Ages, but was rediscovered in 1417 in a monastery in Germany by Poggio Bracciolini. It played an important role both in the development of atomism (Lucretius was an important influence on Pierre Gassendi) and the efforts of various figures of the Enlightenment era to construct a new Christian humanism.

Neopythagoreanism (or neo-Pythagoreanism) was a school of Hellenistic and Ancient Roman philosophy which revived Pythagorean doctrines. Neopythagoreanism was influenced by middle Platonism and in turn influenced Neoplatonism. It originated in the 1st century BC and flourished during the 1st and 2nd centuries AD. The Encyclopædia Britannica Eleventh Edition describes Neopythagoreanism as "a link in the chain between the old and the new" within Hellenistic philosophy. Central to Neopythagorean thought was the concept of a soul and its inherent desire for a unio mystica with the divine. The word Neopythagoreanism is a modern (19th century) term, coined as a parallel of "Neoplatonism".

Iamblichus (/aɪˈæmblɪkəs/ eye-AM-blik-əs; Ancient Greek: Ἰάμβλιχος, romanized: Iámblichos; Aramaic: 𐡉𐡌𐡋𐡊𐡅, romanized: Yamlīkū; c. 245 – c. 325) was a Greek Neoplatonist philosopher who determined a direction later taken by Neoplatonism. Iamblichus was also the biographer of the Greek mystic, philosopher, and mathematician Pythagoras. In addition to his philosophical contributions, his Protrepticus is important for the study of the sophists because it preserved about ten pages of an otherwise unknown sophist known as the Anonymus Iamblichi.