Rational Thinking

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Please copy the text in the edit box below and insert it manually by editing this page. Upon submitting the note will be published multi-licensed under the terms of the CC-BY-SA-3.0 license and of the GFDL, versions 1.2, 1.3, or any later version. How to Disagree. March 2008 The web is turning writing into a conversation.

How to Disagree

Twenty years ago, writers wrote and readers read. The web lets readers respond, and increasingly they do—in comment threads, on forums, and in their own blog posts. Many who respond to something disagree with it. Logic. Logic (from the Ancient Greek: λογική, logike)[1] has two meanings: first, it describes the use of valid reasoning in some activity; second, it names the normative study of reasoning or a branch thereof.[2][3] In the latter sense, it features most prominently in the subjects of philosophy, mathematics, and computer science.


Logic was studied in several ancient civilizations, including India,[4] China,[5] Persia and Greece. In the West, logic was established as a formal discipline by Aristotle, who gave it a fundamental place in philosophy. The study of logic was part of the classical trivium, which also included grammar and rhetoric. List of fallacies. A fallacy is incorrect argument in logic and rhetoric resulting in a lack of validity, or more generally, a lack of soundness.

List of fallacies

Fallacies are either formal fallacies or informal fallacies. Formal fallacies[edit] Appeal to probability – is a statement that takes something for granted because it would probably be the case (or might be the case).[2][3]Argument from fallacy – assumes that if an argument for some conclusion is fallacious, then the conclusion itself is false.Base rate fallacy – making a probability judgement based on conditional probabilities, without taking into account the effect of prior probabilities.[5]Conjunction fallacy – assumption that an outcome simultaneously satisfying multiple conditions is more probable than an outcome satisfying a single one of them.[6]Masked man fallacy (illicit substitution of identicals) – the substitution of identical designators in a true statement can lead to a false one.

Formal fallacy. In philosophy, a formal fallacy is a pattern of reasoning that is always wrong.

Formal fallacy

This is due to a flaw in the logical structure of the argument which renders the argument invalid. A formal fallacy is contrasted with an informal fallacy, which may have a valid logical form and yet be unsound because one or more premises are false. The term fallacy is often used generally to mean an argument that is problematic for any reason, whether it is formal or informal. The presence of a formal fallacy in a deductive argument does not imply anything about the argument's premises or its conclusion. Both may actually be true, or even more probable as a result of the argument, but the deductive argument is still invalid because the conclusion does not follow from the premises in the manner described. Informal logic. Informal logic is associated with (informal) fallacies, critical thinking, the Thinking Skills Movement[6] and the interdisciplinary inquiry known as argumentation theory.

Informal logic

Frans H. van Eemeren writes that the label "informal logic" covers a "collection of normative approaches to the study of reasoning in ordinary language that remain closer to the practice of argumentation than formal logic. "[7] Bias. Bias is an inclination of temperament or outlook to present or hold a partial perspective and a refusal to even consider the possible merits of alternative points of view.


People may be biased toward or against an individual, a race, a religion, a social class, or a political party. Biased means one-sided, lacking a neutral viewpoint, not having an open mind. Bias can come in many forms and is often considered to be synonymous with prejudice or bigotry. Cognitive bias.

A cognitive bias is a pattern of deviation in judgment, whereby inferences about other people and situations may be drawn in an illogical fashion.[1] Individuals create their own “subjective social reality” from their perception of the input.[2] An individual’s construction of social reality, not the objective input, may dictate their behaviour in the social world.[3] Thus, cognitive biases may sometimes lead to perceptual distortion, inaccurate judgment, illogical interpretation, or what is broadly called irrationality.[4][5][6] Some cognitive biases are presumably adaptive.

Cognitive bias

List of cognitive biases. Cognitive biases are tendencies to think in certain ways.

List of cognitive biases

Cognitive biases can lead to systematic deviations from a standard of rationality or good judgment, and are often studied in psychology and behavioral economics. There are also controversies as to whether some of these biases count as truly irrational or whether they result in useful attitudes or behavior. For example, when getting to know others, people tend to ask leading questions which seem biased towards confirming their assumptions about the person.