Analogy: forms, reasoning, and practical uses
An analogy compares two things by highlighting shared features to explain, reason, or generate hypotheses. This article outlines types, cognitive role, historical perspectives, applications, and limits of analogical inference.
Overview
An analogy is a comparison that links two distinct domains by pointing out relevant similarities. People use analogies to simplify complex ideas, form hypotheses, teach concepts, persuade others, and generate creative solutions. Unlike strict deductive proofs, analogical connections usually support conclusions only probabilistically: they suggest that because one thing has certain properties, another similar thing might have them as well. For further reading on the general class of such arguments see inductive reasoning.
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Types and characteristics
Analogies can be expressed in many ways, from a simple metaphor to elaborate structural mappings. Common distinctions include:
- Surface analogies — based on superficial resemblances such as appearance or vocabulary (for example, comparing the human eye to a camera).
- Structural (or deep) analogies — based on parallel relations or functions, where the pattern of relationships in one domain mirrors those in another (for example, comparing electrical circuits to water flow to explain current and resistance).
- Literal vs. figurative — literal analogies compare things within the same broad category, while figurative analogies use poetic or rhetorical language to highlight likeness across categories.
History and theoretical perspectives
Scholars across philosophy, psychology, and cognitive science have long studied analogy as a mode of thought and argument. In philosophy it is treated as an inductive device whose strength depends on the relevance and number of similarities and the absence of disanalogies. Cognitive scientists have developed formal accounts of how people map relations between domains; a prominent framework is the structure-mapping theory, which explains how correspondences between relational systems are identified and prioritized during analogical reasoning.
Uses, examples, and importance
Analogies play a central role in education, science, law, and everyday problem solving. Teachers use analogies to introduce unfamiliar topics; scientists employ analogical models to form testable hypotheses and design experiments; lawyers use analogies between cases to argue for similar legal outcomes. Typical examples include comparing the atom to a solar system (a rough model for electrons orbiting a nucleus) or treating the heart as a pump to convey its function in circulation.
Evaluating analogical arguments and limits
Not every analogy is informative. Good analogical reasoning typically satisfies several criteria: relevance of shared features to the claim being made, number and variety of independent similarities, a lack of critical dissimilarities, and a plausible causal or structural link between the compared aspects. Analogy can mislead when surface resemblances obscure crucial differences or when the mapping ignores important contextual factors. For discussion of methodological attempts to separate strong from weak analogies see work on the criteria of analogical inference at related resources.
History
Antiquity to scholasticism
Analogism was already to be found as a paradeigma in Aristotle (in: first analytics). Theophrastus called this procedure of inference a conclusion from hypothetical premises. The Epicureans consider this procedure (o kata ten omoioteta tropos) as a means from appearances to the unknown. In Boethius this inference is called exemplum. In the theological doctrines of scholasticism the procedure acquires a special value for theological needs, especially with regard to positive statements about the divine conception according to the so-called analogy of being.
Analogies according to scholasticism
While David Hume counts analogy conclusions among the probability conclusions, Wilhelm Wundt classifies them among the subsumption conclusions (in: Logik I).
Approaches to the use of analogies in the general methodology of the natural sciences are first found in Francis Bacon and, in a more developed form, in John Stuart Mill.
Theory
Analogism is not, strictly speaking, a proof - it consists in inferring the uncertain parts of a not fully known system from knowledge of a similar but fully known one. It is therefore primarily an instrument for hypothesizing and has "only heuristic value".
The conclusion by analogy can only be a proof if the two systems, i.e. the mapping and the mapped system, are isomorphic to each other, at least in the corresponding subdomain for which the proof is given, and as long as the appropriate transformation rules are observed.
Conclusions by analogy proved to be extraordinarily fruitful and yielded important partial insights, until the realization of the quantization of energy and orbits in the case of atomic structures made the essential difference between the conditions of a solar system and the atomic structure apparent. This example shows at the same time the problem of analogism: it is a conclusion of probability. In the borderline case the analogy changes into isomorphism, the analogy, which at first is gained partially, i. e. starts from the agreement in some essential properties, structures etc., can be totalized by assigning corresponding elements. On the other hand, conclusions by analogy prove to be false if, apart from all similarity or agreement, an essential difference between the phenomena set in the analogy is demonstrable.
Questions and answers
Q: What is an analogy?
A: An analogy is a comparison between two things that are similar in some way.
Q: Why do people draw analogies?
A: People draw analogies to make a concept easier to understand.
Q: What category of reasoning do analogies belong to?
A: Analogies belong to the category of inductive reasoning.
Q: Do the conclusions of analogies follow with certainty?
A: No, their conclusions do not follow with certainty but are only supported with varying degrees of strength.
Q: What is the difference between superficial and profound analogies?
A: Superficial analogies compare two things that might look alike but work quite differently, while profound analogies compare two things that might look different but work in ways like each other.
Q: What is the goal of finding profound analogies?
A: The goal of finding profound analogies is to teach us something worth knowing.
Q: How does Mario Bunge see analogy?
A: Mario Bunge sees analogy as a main way of getting new hypotheses which can be tested based on similarities in behaviour or structure.
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AlegsaOnline.com Analogy: forms, reasoning, and practical uses Leandro Alegsa
URL: https://en.alegsaonline.com/art/3758
Sources
- plato.stanford.edu : plato.stanford.edu/entries/reasoning-analogy/
- pitt.edu : pitt.edu/~jdnorton/papers/Analogy.pdf