# Deductive reasoning

Deductive reasoning links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true. Deductive reasoning (top-down logic) contrasts with inductive reasoning (bottom-up logic) in the following way: In deductive reasoning, a conclusion is reached reductively by applying general rules that hold over the entirety of a closed domain of discourse, narrowing the range under consideration until only the conclusion(s) is left. In inductive reasoning, the conclusion is reached by generalizing or extrapolating from, i.e., there is epistemic uncertainty. Note, however, that the inductive reasoning mentioned here is not the same as induction used in mathematical proofs – mathematical induction is actually a form of deductive reasoning. Simple example An example of a deductive argument: All men are mortal.Socrates is a man.Therefore, Socrates is mortal. Law of detachment P → Q.

Abductive reasoning Abductive reasoning (also called abduction,[1] abductive inference[2] or retroduction[3]) is a form of logical inference that goes from an observation to a hypothesis that accounts for the observation, ideally seeking to find the simplest and most likely explanation. In abductive reasoning, unlike in deductive reasoning, the premises do not guarantee the conclusion. One can understand abductive reasoning as "inference to the best explanation".[4] The fields of law,[5] computer science, and artificial intelligence research[6] renewed interest in the subject of abduction. Diagnostic expert systems frequently employ abduction. History The American philosopher Charles Sanders Peirce (1839–1914) first introduced the term as "guessing".[7] Peirce said that to abduce a hypothetical explanation from an observed circumstance is to surmise that may be true because then would be a matter of course.[8] Thus, to abduce from involves determining that is sufficient, but not necessary, for allows deriving

Student Resources The Importance of Communication Skills Communication skills—both oral and written—are consistently ranked at the top of the list of skills that employers find most attractive in new college graduates, according to the National Association of Colleges and Employers (NACE) and their annual Job Outlook Surveys. However, the primary complaint from employers about new college graduates is that they lack the requisite speaking and writing skills necessary to perform well in their jobs. Therefore, communication skills can easily be the deciding factor for hiring or not hiring a job candidate, not just in communication intensive positions, but across professions. Resources Public speaking Working in groups Argument and deliberation Audience adaptation Delivery Organization Evidence Reasoning

Faulty generalization A faulty generalization is a conclusion about all or many instances of a phenomenon that has been reached on the basis of just one or just a few instances of that phenomenon.[1] It is an example of jumping to conclusions. For example, we may generalize about all people, or all members of a group, based on what we know about just one or just a few people. If we meet an angry person from a given country X, we may suspect that most people in country X are often angry. If we see only white swans, we may suspect that all swans are white. Faulty generalizations may lead to further incorrect conclusions. Expressed in more precise philosophical language, a fallacy of defective induction is a conclusion that has been made on the basis of weak premises. Logic The proportion Q of the sample has attribute A. Therefore, the proportion Q of the population has attribute A. Inductive fallacies Hasty generalization Examples Hasty generalization usually shows the pattern See also

The Science of Improv Through his studies of the brain "on jazz," music-loving otolaryngologist Charles Limb aims to unravel the mind's secrets of creativity. By Nick Zagorski | Photo by Keith Weller David Kane had never played keyboard quite like this. Sure, the 53-year-old musician and composer had experienced his share of cramped recording studios and poorly tuned pianos during his 37-year career. "Physically, it wasn't too uncomfortable," he jokes today, "but for my creative space, it was horrible." Three-dimensional surface projection of activations and deactivations associated with improvisation during jazz. "How do the legends, musicians like John Coltrane, get up on stage and improvise music for an hour or sometimes more?" Answering those questions appears daunting, as creativity may be the most enigmatic component of the human brain. "During improv, the brain deactivates the area involved in self-censoring, while cranking up the region linked with self-expression," Limb explains.

Reason Reason is the capacity for consciously making sense of things, establishing and verifying facts, applying logic, and changing or justifying practices, institutions, and beliefs based on new or existing information.[1] It is closely associated with such characteristically human activities as philosophy, science, language, mathematics, and art and is normally considered to be a distinguishing ability possessed by humans.[2] Reason, or an aspect of it, is sometimes referred to as rationality. Using reason, or reasoning, can also be described more plainly as providing good, or the best, reasons. For example, when evaluating a moral decision, "morality is, at the very least, the effort to guide one's conduct by reason—that is, doing what there are the best reasons for doing—while giving equal [and impartial] weight to the interests of all those affected by what one does."[7] Etymology and related words Philosophical history Classical philosophy The critique of reason

Inductive reasoning Inductive reasoning (as opposed to deductive reasoning or abductive reasoning) is reasoning in which the premises seek to supply strong evidence for (not absolute proof of) the truth of the conclusion. While the conclusion of a deductive argument is certain, the truth of the conclusion of an inductive argument is probable, based upon the evidence given.[1] The philosophical definition of inductive reasoning is more nuanced than simple progression from particular/individual instances to broader generalizations. Many dictionaries define inductive reasoning as reasoning that derives general principles from specific observations, though some sources disagree with this usage.[2] Description Inductive reasoning is inherently uncertain. An example of an inductive argument: 90% of biological life forms that we know of depend on liquid water to exist. Therefore, if we discover a new biological life form it will probably depend on liquid water to exist. Inductive vs. deductive reasoning

Lecture - Introduction to Argumentation for Debaters - Alfred Snider - WSDA 2011 This is entitled "Introduction to Argumentation for Debaters." The presenter is Dr. Alfred Snider of the University of Vermont. This took place at the Third World Schools Debate Academy, held 2-9 July 2011 in the beautiful Julian Alps, Kranjska Gora, Slovenia and held at the lovely Hotel Kompas, a fabulous four star hotel in a wonderful location. The event was attended by over 130 people from 19 countries, including Macedonia, Italy, Sweden, Czech Republic, Ireland, Serbia, Montenegro, Bosnia, Croatia, Germany, Qatar, Venezuela, Lithuania, Romania, Slovenia, the USA, Italy, Hong Kong and the UK. The program is sponsored by ZIP Slovenia (vimeo.com/​user5582136) and the World Debate Institute University of Vermont USA (debate.uvm.edu/​debateblog/​wdi/​). High school students, trainers, teachers and coaches are welcome to attend future sessions.

Jumping to conclusions Jumping to conclusions (officially the jumping conclusion bias, often abbreviated as JTC, and also referred to as the inference-observation confusion[1]) is a psychological term referring to a communication obstacle where one "judge[s] or decide[s] something without having all the facts; to reach unwarranted conclusions".[2][3] In other words, "when I fail to distinguish between what I observed first hand from what I have only inferred or assumed".[1] Because it involves making decisions without having enough information to be sure that one is right, this can give rise to bad or rash decisions. Subtypes Three commonly recognized subtypes are as follows:[4][5] Mind reading – Where there is a sense of access to special knowledge of the intentions or thoughts of others. Information Jumping to conclusions is a form of cognitive distortion. It is easy for interviewers to jump to conclusions, often resulting in a "costly hiring error due to false inference". Comedy

Gravity Attraction of masses and energy In physics, gravity (from Latin gravitas 'weight'[1]) is a fundamental interaction which causes mutual attraction between all things that have mass. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles.[2] However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light. On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans (the corresponding antipodal tide is caused by the inertia of the Earth and Moon orbiting one another). Definitions History Ancient world In the ancient Middle East, gravity was a topic of fierce debate. Specifics

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Deductive Reasoning - The philosophical idea that underpins the style of research in which the investigator begins from a theoretical position and sets out to test it by gathering and analysing data. It is sometimes called the hypothetico-deductive method because, in experimental research, the researcher normally outlines a hypothesis based on the theory, and then uses empirical methods to see whether it is confirmed or not.

Found in: Davies, M. (2007) Doing a Successful Research Project: Using Qualitative or Quantitative Methods. Basingstoke, Hampshire, England, United Kingdom: Palgrave Macmillan. ISBN: 9781403993793. by Jul 31

Deductive Reasoning - An approach to research where the researcher predicts a relationship between the independent and dependent variables, stating it as a hypothesis. The hypothesis is then tested to see if it is true or false. Comes under the logic of reasoning.

Found in: Glossary of Key Terms: by Jul 31

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