Argument

Analogy

Overview

Analogy is a comparison or correspondence between two things (or two groups of things) because of a third element that they are considered to share.

Logically, it is an inference or an argument from one particular to another particular, as opposed to deduction, induction, and abduction. It is also used where at least one of the premises, or the conclusion, is general rather than particular in nature. It has the general form A is to B as C is to D.

In a broader sense, analogical reasoning is a cognitive process of transferring meaning or information of a particular subject (the analog, or source) onto another (the target); and also the linguistic expression corresponding to such a process. The term analogy can also refer to the relation between the source and the target themselves, which is often (though not always) a similarity, as in the biological notion of analogy.

Analogy plays a significant role in human thought processes. It has been argued that analogy lies at "the core of cognition".

Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).

In the original texts

Passages from public-domain books where Analogy is discussed.

Of Analogy. § 1. The word Analogy, as the name of a mode of reasoning, is generally taken for some kind of argument supposed to be of an inductive nature, but not amounting to a complete induction. There is no word, however, which is used more loosely, or in a greater variety of senses, than Analogy. It sometimes stands for arguments which may be examples of the most rigorous induction. Archbishop Whately, for…
John Stuart Mill, A System of Logic, Ratiocinative and Inductive
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It is often argued, for example: The earth is a celestial body, so is the moon, and it is therefore in all probability inhabited as well as the earth. The analogy is not one whit better than that previously mentioned. That the earth is inhabited does not depend on its being a celestial body, but in other conditions, such as the presence of an atmosphere, and of water in connexion with the atmosphere, &c.: and these…
Georg Wilhelm Friedrich Hegel, The Logic of Hegel
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In analogy attention is turned from the number of observed instances to their character, and, because particulars have some feature in common, they are supposed to be the same in still other respects. While the best we can reach in analogy is probability, the arguments may be such as to result in a high degree of certainty. The form of the argument is valuable in so far as we are able to distinguish between…
John Dewey, Studies in Logical Theory
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But where the objects have not so exact a similarity, the analogy is less perfect, and the inference is less conclusive; though still it has some force, in proportion to the degree of similarity and resemblance. The anatomical observations, formed upon one animal, are, by this species of reasoning, extended to all animals; and it is certain, that when the circulation of the blood, for instance, is clearly proved to…
David Hume, An Enquiry Concerning Human Understanding
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The analogy between individual organisms and the social organism, is one that has from early days occasionally forced itself on the attention of the observant. And though modern science does not countenance those crude ideas of this analogy which have been from time to time expressed since the Greeks flourished; yet it tends to show that there _is_ an analogy, and a remarkable one. While it is becoming clear that…
Herbert Spencer, Essays
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Analogy

Overview

In the original texts

Philosophers who discussed Analogy

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