Fictionalism — is a methodological theory in philosophy that suggests that statements of a certain sort should not be taken to be literally true, but merely as a useful fiction. Two important strands of fictionalism are modal fictionalism (which states that… … Wikipedia
Modal logic — is a type of formal logic that extends classical propositional and predicate logic to include operators expressing modality. Modals words that express modalities qualify a statement. For example, the statement John is happy might be qualified by… … Wikipedia
Modal operator — In modal logic, a modal operator is an operator which forms propositions from propositions. In general, a modal operator has the formal property of being non truth functional, and is intuitively characterised by expressing a modal attitude (such… … Wikipedia
Epistemic modal logic — is a subfield of modal logic that is concerned with reasoning about knowledge. While epistemology has a long philosophical tradition dating back to Ancient Greece, epistemic logic is a much more recent development with applications in many fields … Wikipedia
Outline of logic — The following outline is provided as an overview of and topical guide to logic: Logic – formal science of using reason, considered a branch of both philosophy and mathematics. Logic investigates and classifies the structure of statements and… … Wikipedia
David Kellogg Lewis — Infobox Philosopher region = Western Philosophy era = 20th century philosophy color = #B0C4DE name = David Kellogg Lewis birth = September 28, 1941 flagicon|USA|size=20px Oberlin, Ohio death = October 14, 2001 flagicon|USA|size=20px Princeton,… … Wikipedia
Philosophical realism — Contemporary philosophical realism is the belief that our reality, or some aspect of it, is ontologically independent of our conceptual schemes, linguistic practices, beliefs, etc. Realism may be spoken of with respect to other minds, the past,… … Wikipedia
Philosophy of mathematics — The philosophy of mathematics is the branch of philosophy that studies the philosophical assumptions, foundations, and implications of mathematics. The aim of the philosophy of mathematics is to provide an account of the nature and methodology of … Wikipedia
Logicism — is one of the schools of thought in the philosophy of mathematics, putting forth the theory that mathematics is an extension of logic and therefore some or all mathematics is reducible to logic.[1] Bertrand Russell and Alfred North Whitehead… … Wikipedia
Natural deduction — In logic and proof theory, natural deduction is a kind of proof calculus in which logical reasoning is expressed by inference rules closely related to the natural way of reasoning. This contrasts with the axiomatic systems which instead use… … Wikipedia
