ArcesilausArcesilaus (ˌɑːrsɛsɪˈleɪ.əs; Ἀρκεσίλαος; 316/5–241/0 BC) was a Greek Hellenistic philosopher. He was the founder of Academic Skepticism and what is variously called the Second or Middle or New Academy – the phase of the Platonic Academy in which it embraced philosophical skepticism. Arcesilaus succeeded Crates of Athens as the sixth scholarch of the Academy around 264 BC. He did not preserve his thoughts in writing, so his opinions can only be gleaned second-hand from what is preserved by later writers.
SkepticismSkepticism, also spelled scepticism in British English, is a questioning attitude or doubt toward knowledge claims that are seen as mere belief or dogma. For example, if a person is skeptical about claims made by their government about an ongoing war then the person doubts that these claims are accurate. In such cases, skeptics normally recommend not disbelief but suspension of belief, i.e. maintaining a neutral attitude that neither affirms nor denies the claim.
EpochéIn Hellenistic philosophy, Epoché (ἐποχή epokhē, "cessation") is suspension of judgment but also as "withholding of assent". Pyrrhonism Epoché plays an important role in Pyrrhonism, the skeptical philosophy named after Pyrrho, who is regarded as the founder of ancient skepticism. The Pyrrhonists developed the concept of "epoché" to describe the state where all judgments about non-evident matters are suspended to induce a state of ataraxia (freedom from worry and anxiety).
CyrenaicsThe Cyrenaics or Kyrenaics (Kyrēnaïkoí), were a sensual hedonist Greek school of philosophy founded in the 4th century BCE, supposedly by Aristippus of Cyrene, although many of the principles of the school are believed to have been formalized by his grandson of the same name, Aristippus the Younger. The school was so called after Cyrene, the birthplace of Aristippus. It was one of the earliest Socratic schools. The Cyrenaics taught that the only intrinsic good is pleasure, which meant not just the absence of pain (as it did for Epicurus), but positively enjoyable sensations.
Agrippa the SkepticAgrippa (Ἀγρίππας) was a Pyrrhonist philosopher who probably lived towards the end of the 1st century CE. He is regarded as the author of "The Five Tropes (or Modes, in τρόποι) of Agrippa", which are purported to establish the necessity of suspending judgment (epoché). Agrippa's arguments form the basis of the Agrippan trilemma. Sextus Empiricus described these "modes" or "tropes" in Outlines of Pyrrhonism, attributing them "to the more recent skeptics"; Diogenes Laërtius attributes them to Agrippa.
PhenomenonA phenomenon (: phenomena), sometimes spelled phaenomenon, is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which cannot be directly observed. Kant was heavily influenced by Gottfried Wilhelm Leibniz in this part of his philosophy, in which phenomenon and noumenon serve as interrelated technical terms. Far predating this, the ancient Greek Pyrrhonist philosopher Sextus Empiricus also used phenomenon and noumenon as interrelated technical terms.
Three marks of existenceIn Buddhism, the three marks of existence are three characteristics (Pali: tilakkhaṇa; Sanskrit: त्रिलक्षण trilakṣaṇa) of all existence and beings, namely aniccā (impermanence), dukkha (commonly translated as "suffering", "unsatisfactory," "unease"), and anattā (without a lasting essence). That humans are subject to delusion about the three marks, that this delusion results in suffering, and that removal of that delusion results in the end of dukkha, is a central theme in the Buddhist Four Noble Truths and Noble Eightfold Path.
AjñanaAjñāna (अज्ञान) was one of the nāstika or "heterodox" schools of ancient Indian philosophy, and the ancient school of radical Indian skepticism. It was a Śramaṇa movement and a major rival of early Buddhism, Jainism and the Ājīvika school. They have been recorded in Buddhist and Jain texts. They held that it was impossible to obtain knowledge of metaphysical nature or ascertain the truth value of philosophical propositions; and even if knowledge was possible, it was useless and disadvantageous for final salvation.
Regress argumentIn epistemology, the regress argument is the argument that any proposition requires a justification. However, any justification itself requires support. This means that any proposition whatsoever can be endlessly (infinitely) questioned, resulting in infinite regress. It is a problem in epistemology and in any general situation where a statement has to be justified. The argument is also known as diallelus (Latin) or diallelon, from Greek di' allelon "through or by means of one another" and as the epistemic regress problem.
DogmaDogma in the broad sense is any belief held unquestioningly and with undefended certainty. It may be in the form of an official system of principles or doctrines of a religion, such as Roman Catholicism, Judaism, or Protestantism, as well as the positions of a philosopher or of a philosophical school such as Stoicism. It may also be found in political belief systems, such as fascism, progressivism, liberalism, and conservatism. In the pejorative sense, dogma refers to enforced decisions, such as those of aggressive political interests or authorities.
