Concepts in ancient Greek epistemology

Dogma, in its broadest sense, is any belief held definitively and without the possibility of reform. It may be in the form of an official system of principles or doctrines of a religion, such as Judaism, Roman Catholicism, Protestantism, or Islam, the positions of a philosopher or philosophical school, such as Stoicism, and political belief systems such as fascism, socialism, progressivism, liberalism, and conservatism.

allegory by Plato

thumb|Greek alphabet|Greek spelling of logos|class=skin-invert-image

one of the Delphic maxims

thumb|right|upright=1.2|This diagram shows the medieval understanding of celestial spheres|spheres of the [[cosmos, derived from Aristotle, and as per the standard explanation by Ptolemy. It came to be understood that at least the outermost sphere (marked "Primũ Mobile") has its own intellect, intelligence or nous – a cosmic equivalent to the human mind.]]

In philosophy, an aporia () is a conundrum or state of puzzlement. In rhetoric, it is a declaration of doubt, made for rhetorical purpose and often feigned. The notion of an aporia is principally found in ancient Greek philosophy, but it also plays a role in modern post-structuralist philosophy, as in the writings of Jacques Derrida and Luce Irigaray, and it has also served as an instrument of investigation in analytic philosophy.

Gnosis is the common Greek noun for knowledge (γνῶσις, gnōsis, f.). The term was used among various Hellenistic religions and philosophies in the Greco-Roman world. It is best known for its implication within Gnosticism, where it signifies a spiritual knowledge or insight into humanity's real nature as divine, leading to the deliverance of the divine spark within humanity from the constraints of earthly existence.

In philosophy, '''' (; ) is knowledge or understanding. The term epistemology'' (the branch of philosophy concerning knowledge) is derived from .

Adiaphoron (; plural: adiaphora; from the Greek (pl. ), meaning 'not different or differentiable') is the negation of diaphora, 'difference'.

In Hellenistic philosophy, epoché (also epoche; pronounced or ) is suspension of judgment but also "withholding of assent".

concept in Plato's epistemological and psychological theory

Doxa (; from verb ) is a common belief or popular opinion. In classical rhetoric, doxa is contrasted with episteme ('knowledge').

Platonic philosophical analogy

Acatalepsy (from the Greek and ), in philosophy, is incomprehensibleness, or the impossibility of comprehending or conceiving some or all things. The doctrine held by the ancient Skeptic philosophers, that human knowledge never amounts to certainty, but only to probability.

In Ancient Greek philosophy, techne (; , ) is a philosophical concept that refers to making or doing. Today, while the Ancient Greek definition of techne is similar to the modern definition and use of "practical knowledge", techne can include various fields such as mathematics, geometry, medicine, shoemaking, rhetoric, philosophy, music, and astronomy.

Diairesis (, "division") is a form of classification used in ancient (especially Platonic) logic that serves to systematize concepts and come to definitions. When defining a concept using diairesis, one starts with a broad concept, then divides this into two or more specific sub-concepts, and this procedure is repeated until a definition of the desired concept is reached. Aristotle makes extensive use of diaresis in categorization as basis for syllogizing. He makes clear, however, that definition by diaresis does not in itself prove anything. Apart from this definition, the procedure also resu

superlative concept in the philosophy of Plato

Platonic philosophical analogy

philosophical problem about knowledge

Katalepsis (, "grasping") is a term in Stoic philosophy for a concept roughly equivalent to modern comprehension. To the Stoic philosophers, katalepsis was an important premise regarding one's state of mind as it relates to grasping fundamental philosophical concepts, which was followed by the assent, or adherence to the truth thus understood.