AenesidemusAenesidemus (Αἰνησίδημος or Αἰνεσίδημος) was a 1st-century BC Greek Pyrrhonist philosopher from Knossos who revived the doctrines of Pyrrho and introduced ten skeptical "modes" (tropai) for the suspension of judgment. He broke with the Academic Skepticism that was predominant in his time, synthesizing the teachings of Heraclitus and Timon of Phlius with philosophical skepticism. Although his primary work, the Pyrrhonian Discourses, has been lost, an outline of the work survives from the later Byzantine empire, and the description of the modes has been preserved by few ancient sources.
ReliabilismReliabilism, a category of theories in the philosophical discipline of epistemology, has been advanced as a theory both of justification and of knowledge. Process reliabilism has been used as an argument against philosophical skepticism, such as the brain in a vat thought experiment. Process reliabilism is a form of epistemic externalism. A broadly reliabilist theory of knowledge is roughly as follows: One knows that p (p stands for any proposition—e.g.
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.
InfinitismInfinitism is the view that knowledge may be justified by an infinite chain of reasons. It belongs to epistemology, the branch of philosophy that considers the possibility, nature, and means of knowledge. Since Gettier, "knowledge" is no longer widely accepted as meaning "justified true belief" only. However, some epistemologists still consider knowledge to have a justification condition. Traditional theories of justification (foundationalism and coherentism) and indeed some philosophers consider an infinite regress not to be a valid justification.
SubjectivismSubjectivism is the doctrine that "our own mental activity is the only unquestionable fact of our experience", instead of shared or communal, and that there is no external or objective truth. While Thomas Hobbes was an early proponent of subjectivism, the success of this position is historically attributed to Descartes and his methodic doubt. He used it as an epistemological tool to prove the opposite (an objective world of facts independent of one's own knowledge, ergo the "Father of Modern Philosophy" inasmuch as his views underlie a scientific worldview).
KantianismKantianism is the philosophy of Immanuel Kant, a German philosopher born in Königsberg, Prussia (now Kaliningrad, Russia). The term Kantianism or Kantian is sometimes also used to describe contemporary positions in philosophy of mind, epistemology, and ethics. Kantian ethics Kantian ethics is deontological, revolving entirely around duty rather than emotions or end goals. All actions are performed in accordance with some underlying maxim or principle, which are vastly different from each other; it is according to this that the moral worth of any action is judged.
Circular reasoningCircular reasoning (circulus in probando, "circle in proving"; also known as circular logic) is a logical fallacy in which the reasoner begins with what they are trying to end with. Circular reasoning is not a formal logical fallacy, but a pragmatic defect in an argument whereby the premises are just as much in need of proof or evidence as the conclusion, and as a consequence the argument fails to persuade. Other ways to express this are that there is no reason to accept the premises unless one already believes the conclusion, or that the premises provide no independent ground or evidence for the conclusion.
