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t. e. Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or logical truths. It studies how conclusions follow from premises due to the structure of arguments alone, independent of their topic and content.
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logic, the study of correct reasoning, especially as it involves the drawing of inferences.
This article discusses the basic elements and problems of contemporary logic and provides an overview of its different fields. For treatment of the historical development of logic, see logic, history of. For detailed discussion of specific fields, see the articles applied logic, formal logic, modal logic, and logic, philosophy of.
An inference is a rule-governed step from one or more propositions, called premises, to a new proposition, usually called the conclusion. A rule of inference is said to be truth-preserving if the conclusion derived from the application of the rule is true whenever the premises are true. Inferences based on truth-preserving rules are called deductive, and the study of such inferences is known as deductive logic. An inference rule is said to be valid, or deductively valid, if it is necessarily truth-preserving. That is, in any conceivable case in which the premises are true, the conclusion yielded by the inference rule will also be true. Inferences based on valid inference rules are also said to be valid.
(Read Steven Pinker’s Britannica entry on rationality.)
Logic in a narrow sense is equivalent to deductive logic. By definition, such reasoning cannot produce any information (in the form of a conclusion) that is not already contained in the premises. In a wider sense, which is close to ordinary usage, logic also includes the study of inferences that may produce conclusions that contain genuinely new information. Such inferences are called ampliative or inductive, and their formal study is known as inductive logic. They are illustrated by the inferences drawn by clever detectives, such as the fictional Sherlock Holmes.
The contrast between deductive and ampliative inferences may be illustrated in the following examples. From the premise “somebody envies everybody,” one can validly infer that “everybody is envied by somebody.” There is no conceivable case in which the premise of this inference is true and the conclusion false. However, when a forensic scientist infers from certain properties of a set of human bones the approximate age, height, and sundry other characteristics of the deceased person, the reasoning used is ampliative, because it is at least conceivable that the conclusions yielded by it are mistaken.
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logic: [noun] a science that deals with the principles and criteria of validity of inference and demonstration : the science of the formal principles of reasoning. a branch or variety of logic. the formal principles of a branch of knowledge. a particular mode of reasoning viewed as valid or faulty. relevance, propriety. interrelation or ...
LOGIC definition: 1. a particular way of thinking, especially one that is reasonable and based on good judgment: 2…. Learn more.
Logic definition: the science that investigates the principles governing correct or reliable inference.. See examples of LOGIC used in a sentence.
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Finally, logic itself is the source of fascinating philosophical questions. The basic question at its heart—what is it for a claim to follow from others?—ramifies out in myriad directions, providing fertile ground for philosophical speculation. There is logic, and then there is philosophy of logic. Logic is said to be “formal,” for example.
logic. philosophy of logic, the study, from a philosophical perspective, of the nature and types of logic, including problems in the field and the relation of logic to mathematics and other disciplines. The term logic comes from the Greek word logos. The variety of senses that logos possesses may suggest the difficulties to be encountered in ...
