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Glossary of Philosophical Terms
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Page under construction: It will take several months to bring this page up to date. The first time that a term is defined in a study unit, it appears in bold. Codes in square brackets at the end of each definition below refer to the webpage or study unit where the term was first defined i.e. CT - Classic Text, CR - Critical Reasoning, H - Homepage. Click the code to take you directly to the relevant document.

addition  an elementary valid argument of the form: A /∴ A or B [CR02]

ad hominem  a fallacy that involves an attack or casting aspersions upon the arguer, rather than dealing with the argument itself – a.k.a. playing the man and not the ball [CR04]

aesthetics  that branch of philosophy that deals with questions of beauty and artistic appreciation [H]

affirming the consequent  a fallacy involving a conditional statement and another statement which confirms that the consequent of the conditional is true and then erroneously concludes that the antecedent must therefore be true [CR02]

analogy  a form of inference that allows the transfer of information or meaning from one particular (the source) to another particular (the target), both of which are similar in important respects [CR03]

antecedent  the “if…” clause of a conditional statement – also called the protasis [CR02]

appeal to authority  a fallacy in which a claimed authority is used to support the conclusion; L ab auctoritate or ad verecundiam [CR04]

appeal to ignorance  a fallacy that invokes ignorance about some matter to draw attention away from the main argument instead of engaging with it; L. ad ignorantiam [CR04]

appeal to the majority  a fallacy in which a majority opinion or sentiment is used as a premise; L. ad populum [CR04]

argument  an interconnected series of propositions intended to support one or more conclusions [CR01]

artefact  (in the sciences) something that is observed that is not naturally present, but occurs as a result of some preparative or investigative procedure [CR17]

begging the question  A fallacy that assumes, as one of its premises, what the argument is intended to prove - a.k.a. circular argument; L. petitio principia [CR04]

category mistake  1. a semantic or ontological mistake in which things belonging to one category are treated as if they belong to a different category [CT04] 2. the misattribution of a property to a thing that could not possibly have such a property [CR04]

causal loop  a circular series of causes and effects e.g. A causing B, causing C, causing A [CT03]

circular argument  see begging the question

cogent  a strong (inductive) argument whose premises are all true [CR03]

conclusion  a declarative statement within an argument that is supported by one or more premises within the argument [CR01]

conditional  a statement of the form: “if… then…” [CR02]

conjunction  an elementary valid argument of the form: A, B /∴ A and B [CR02]

consequent  the “then…” clause of a conditional statement – also called the apodosis [CR02]

constructive dilemma  an elementary valid argument of the form: if A then B and if C then D, A or C /∴ B or D [CR02]

contingent being  one that does not exist in and of itself, but depends for its existence upon some other being or entity [CT03]

cosmological argument  several arguments of the same form that that purport to prove the existence of God based on conceptions causality or necessity [CT03]

critical reasoning  an attitude of being disposed to consider in a thoughtful way the problems and subjects that come within the range of one’s experiences; knowledge of the methods of logical inquiry and reasoning, and some skill in applying those methods [CR01]

declarative statement  a sentence that makes a statement. Declarative statements must be distinguished from interrogatives that ask a question, imperatives or exhortations that give an order, subjunctives that propose hypotheticals, and exclamations that express surprise, strong emotion or pain. [CR01]

deductive  an argument or process of reasoning that moves from one or more statements (premises) to reach a logically certain conclusion [CR02]

denying the antecedent  a fallacy involving a conditional statement and another statement which denies that the antecedent of the conditional is true and then erroneously concludes that the consequent must therefore be false [CR02]

destructive dilemma  an elementary valid argument of the form: if A then B and if C then D, not B or not D /∴ not A or not C [CR02]

disjunctive syllogism  an elementary valid argument of the form: A or B, not A /∴ B [CR02]

doxastic  pertaining to belief [CT04] [CR23]

dualism  1. the belief that the world is comprised of two fundamentally different substances 2. Cartesian dualism holds that body and mind are distinct and separate substances [CT02]

elementary rules of inference  basic valid argument forms that can be used in proofs without having to demonstrate their validity on each subsequent occasion [CR02]

enthymeme  an argument with one or more missing or unstated premises [CR01]

epistemology  that branch of philosophy that deals with knowledge, knowledge acquisition, and the limits of knowledge [H]

escape clause  (in an argument) allows the conclusion to escape being false, even or especially in the case of something unforeseen [CR03]

ethics  that branch of philosophy that deals with questions of value and morality [H]

fallacy  an argument that relies on invalid or faulty reasoning [CR02] q.v. formal fallacy; material fallacy; verbal fallacy See detailed discussion [CR04] and [CR06].

fallacy of accident  the application of a general rule to a particular case, in which some special circumstance or “accident” exempts the rule from applying – a.k.a. sweeping generalization; L. Dicto simpliciter ad dictum secundum quid or simply, Dicto simpliciter [CR04]

fallacy of distraction  one that draws attention away from the argument proper by irrelevant means such as emotionalism [CR04] q.v. fallacy of relevance

fallacy of evidence  one that does not support the conclusion with sufficient evidence [CR04]

fallacy of relevance  one that does not support the conclusion because it is simply irrelevant [CR04] q.v. fallacy of distraction

false dilemma  a fallacy that presents a choice between two divergent situations as if they were the only possibilities, and then demands that we choose one way or the other - a.k.a. false dichotomy or bifurcation [CR04]

faulty analogy  one that results from comparisons being drawn between objects or situations that share very few or no relevant similarities [CR04]

formal fallacy  one that involves some defect in the structure of an argument [CR04]

game theory  the study of analogous models of strategic decision making by rational agents under conditions of conflict and cooperation [CR03]

guilt by association  a fallacy which assumes that because two or more people know each other or are associated with each other, one person’s presumed guilt is associated with the other [CR04]

hasty generalisation  a weak inductive argument from a few instances to a general conclusion that isn’t warranted [CR04]

hypothetical syllogism  an elementary valid argument of the form: if A then B, if B then C /∴ if A then C [CR02]

inductive reasoning  a method of reasoning from a number of supporting premises such that each additional supporting premise makes the conclusion more probable, but not certain [CR03]

inference  the movement in reasoning from premises to one or more logical conclusions supported by the premises [CR01] q.v. elementary rules of inference

irrelevant conclusion  a fallacy of distraction that diverts attention away from the argument proper rather than engaging with it – a.k.a. “red herring”; L ignoratio elenchi [CR04]

loaded or leading question  one that contains one or more controversial or unjustified assumptions (such as guilt), that restrict the choice of an answer [CR04]

material fallacy  one that involves some problem concerning the facts of the matter being argued [CR04]

metaphysics  that branch of philosophy that deals with questions of ultimate reality and existence (ontology) [H]

modus ponens  an elementary valid argument of the form: if A then B, A /∴ B [CR02]

modus tollens  an elementary valid argument of the form: if A then B, not B /∴ not A [CR02]

necessary being  one that is impossible not to exist [CT03]

non sequitur  a fallacy so called because it simply does not follow – usually reserved for fallacies that defy classification [CR04]

ontological argument  an argument that purports to prove the existence of God based on one conception of existence [CT03]

philosophy  1. the most general of disciplines, relying principally on rational argument 2. that field of study that concerns itself especially with metaphysics, epistemology, logic, ethics and aesthetics 3. thinking about thinking [H]

poisoning the well  a fallacy in which prejudicial information is presented in order to discredit or ridicule a target before she has had a chance to state her case [CR04]

positive feedback  a characteristic of any system in which the output of the system is fed back into the input in such a way as to increase the output even more e.g. O produces more of I which in turn produces even more of O [CT03]

premise  a declarative statement assumed to be true that together with other premises support one or more conclusions within an argument [CR01] Major premise and minor premise q.v. syllogism

proposition  the content or meaning expressed by a declarative statement - Propositions are bearers of truth value and may be the objects of belief, and other propositional attitudes. [CR01]

sentential calculus  a.k.a. propositional calculus that deals with propositions expressed by sentences (which may be true or false) as well as their involvement in argument [CR02]

simplification  an elementary valid argument of the form: A and B /∴ A [CR02]

sound  a valid argument whose premises are all true [CR02]

straw man fallacy  one that misrepresents an opponent’s position in an absurd or ridiculous manner which is easily refuted - The image is of a proponent dressed up as a scarecrow, which the opponent then proceeds to demolish. [CR04]

strong  an inductive argument that is well structured such the truth of the premises makes the truth of the conclusion highly probable cf. weak [CR03]

sweeping generalization  see fallacy of accident

syllogism  a classic form of a deductive argument often comprising of a general statement (the major premise) and a specific statement (the minor premise) from which a conclusion may be validly derived E.g. All men are mortal. Socrates is a man. / Therefore, Socrates is mortal. [CR02]

truth value  a value indicating the relation of a proposition to truth - In classical logic there are two truth values: true and false. [CR01]

valid  1. a deductive argument that is structured in such a way that it is impossible for the premises to be true and the conclusion(s) false [CR02] 2. an instrument that measures what it is supposed to or is intended to measure [CR26]

verbal fallacy  one that involves some problem with the way that it is worded [CR04]

weak  an inductive argument in which the truth of the premises makes the truth of the conclusion only slightly probable cf. strong [CR03]

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