Problem of inductionFirst formulated by David Hume, the problem of induction questions our reasons for believing that the future will resemble the past, or more broadly it questions predictions about unobserved things based on previous observations. This inference from the observed to the unobserved is known as "inductive inferences", and Hume, while acknowledging that everyone does and must make such inferences, argued that there is no non-circular way to justify them, thereby undermining one of the Enlightenment pillars of rationality.
Absolute idealismAbsolute idealism is chiefly associated with Friedrich Schelling and G. W. F. Hegel, both of whom were German idealist philosophers in the 19th century. The label has also been attached to others such as Josiah Royce, an American philosopher who was greatly influenced by Hegel's work, and the British idealists. According to Hegel, being is ultimately comprehensible only as an all-inclusive whole (das Absolute).
Correspondence theory of truthIn metaphysics and philosophy of language, the correspondence theory of truth states that the truth or falsity of a statement is determined only by how it relates to the world and whether it accurately describes (i.e., corresponds with) that world. Correspondence theories claim that true beliefs and true statements correspond to the actual state of affairs. This type of theory attempts to posit a relationship between thoughts or statements on one hand, and things or facts on the other.
Critical rationalismCritical rationalism is an epistemological philosophy advanced by Karl Popper on the basis that, if a statement cannot be logically deduced (from what is known), it might nevertheless be possible to logically falsify it. Following Hume, Popper rejected any inductive logic that is ampliative, i.e., any logic that can provide more knowledge than deductive logic. In other words if we cannot assert it logically, we should at the least try to logically falsify it, which led Popper to his falsifiability criterion.
Logical atomismLogical atomism is a philosophical view that originated in the early 20th century with the development of analytic philosophy. It holds that the world consists of ultimate logical "facts" (or "atoms") that cannot be broken down any further, each of which can be understood independently of other facts. Its principal exponent was the British philosopher Bertrand Russell. It is also widely held that the early works of his Austrian-born pupil and colleague, Ludwig Wittgenstein, defend a version of logical atomism, though he went on to reject it in his later Philosophical Investigations.
Two Dogmas of Empiricism"Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951. According to University of Sydney professor of philosophy Peter Godfrey-Smith, this "paper [is] sometimes regarded as the most important in all of twentieth-century philosophy".
OperationalizationIn research design, especially in psychology, social sciences, life sciences and physics, operationalization or operationalisation is a process of defining the measurement of a phenomenon which is not directly measurable, though its existence is inferred from other phenomena. Operationalization thus defines a fuzzy concept so as to make it clearly distinguishable, measurable, and understandable by empirical observation. In a broader sense, it defines the extension of a concept—describing what is and is not an instance of that concept.
Berlin CircleThe Berlin Circle (die Berliner Gruppe) was a group that maintained logical empiricist views about philosophy. Berlin Circle was created in the late 1920s by Hans Reichenbach, Kurt Grelling and Walter Dubislav and composed of philosophers and scientists such as Carl Gustav Hempel, David Hilbert and Richard von Mises. Its original name was Die Gesellschaft für empirische Philosophie, which in English may be translated as "the society for empirical philosophy".
EmotivismEmotivism is a meta-ethical view that claims that ethical sentences do not express propositions but emotional attitudes. Hence, it is colloquially known as the hurrah/boo theory. Influenced by the growth of analytic philosophy and logical positivism in the 20th century, the theory was stated vividly by A. J. Ayer in his 1936 book Language, Truth and Logic, but its development owes more to C. L. Stevenson. Emotivism can be considered a form of non-cognitivism or expressivism.
UnobservableAn unobservable (also called impalpable) is an entity whose existence, nature, properties, qualities or relations are not directly observable by humans. In philosophy of science, typical examples of "unobservables" are the force of gravity, causation and beliefs or desires. The distinction between observable and unobservable plays a central role in Immanuel Kant's distinction between noumena and phenomena as well as in John Locke's distinction between primary and secondary qualities.
