Accessed 11 Nov. More Definitions for theory. Nglish: Translation of theory for Spanish Speakers. Britannica English: Translation of theory for Arabic Speakers. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Log in Sign Up. Save Word. Essential Meaning of theory. There are a number of different theories about the cause of the disease. See More Examples She proposed a theory of her own. Investigators rejected the theory that the death was accidental.
There is no evidence to support such a theory. Full Definition of theory. Synonyms for theory Synonyms hypothesis , proposition , supposition , thesis Visit the Thesaurus for More.
Choose the Right Synonym for theory hypothesis , theory , law mean a formula derived by inference from scientific data that explains a principle operating in nature. The Difference Between Hypothesis and Theory A hypothesis is an assumption, an idea that is proposed for the sake of argument so that it can be tested to see if it might be true. Examples of theory in a Sentence The immune surveillance theory of cancer holds that in a way we all do have cancer, that a healthy immune system fights off rogue cells as they appear.
Doctorow , Loon Lake , While strolling around, we kept the run of the moon all the time, and we still kept an eye on her after we got back to the hotel portico. I had a theory that the gravitation of refraction, being subsidiary to atmospheric compensation, the refrangibility of the earth's surface would emphasize this effect in regions where great mountain ranges occur, and possibly so even-handed impact the odic and idyllic forces together, the one upon the other, as to prevent the moon from rising higher than 12, feet above sea-level.
This daring theory had been received with frantic scorn by some of my fellow-scientists, and with an eager silence by others. She proposed a theory of her own. He is a specialist in film theory and criticism. Recent Examples on the Web The third map is subject to regular amendments, just like any other bill, so in theory , lawmakers could draw their own maps at that point.
Haynes, Milwaukee Journal Sentinel , 5 Nov. First Known Use of theory , in the meaning defined at sense 6. Despite the differences between these two views, the empirical evidence taken to support the Theory-Theory does not generally discriminate between them, nor have psychologists always been careful to mark these distinctions. As with many debates over representational posits, the views in question generate differing predictions only in combination with supplementary assumptions about cognitive processing and resources.
However, there may be theoretical reasons for preferring one view over the other; these will be discussed further in section 5. Much of the support for the Theory-Theory comes from developmental studies. The youngest children understand eating, breathing, digesting, and so forth, mainly as human behaviors, and they explain them in terms of human needs, desires, plans, and conventions.
Over time, children build various new accounts of bodies, initially treating them as simple containers and finally differentiating them into separate organs that have their own biological functions.
Four and five year olds are reluctant to attribute animal properties—even eating and breathing—to living beings other than humans. The primacy of people in biology carries over to judgments of similarity, with adults displaying a smooth gradient of similarity between people and other living things and six year olds seeing a sharp dividing line between people and the rest of the animal kingdom, including mammals.
Finally, in inductive projection tasks people are clearly paradigmatic for four year olds: if told that a person has an organ called a spleen, they will project having a spleen to dogs and bees, but rarely the opposite.
By age 10, people are seen as no longer unique in this respect. Indeed, the very concept living thing comes to be acquired as this knowledge develops. Characteristic features are akin to prototypes: compilations of statistically significant but possibly superficial properties found in categories.
Defining features, on the other hand, are those that genuinely make something the kind of thing that it is, regardless of how well it corresponds to the observed characteristics.
In a series of discovery studies , Keil gave children descriptions of objects that have the characteristic features belonging to a natural kind, but which were later discovered to have the plausible defining features of a different kind; for example, an animal that looks and acts like a horse but which is discovered to have the inside parts of cows as well as cow parents and cow babies.
While at age five, children thought these things were horses, by age seven they were more likely to think them cows, and adults were nearly certain these were cows. Defining features based on biology internal structure, parentage come to dominate characteristic features appearance, behavior. In a related series of transformation studies , children heard about a member of a natural kind which underwent some sort of artificial alterations to its appearance, behavior, and insides; for example, a raccoon that was dyed to look like a skunk and operated on so that it produces a foul, skunk-like odor.
This effect was notably stronger for biological kinds than mineral kinds; however, children at all ages strongly resisted the idea that a member of a biological kind could be turned into something from a different ontological category for example, an animal cannot be turned into a plant. As this network of causal principles becomes more enriched they recognize that the category members are defined by the presence of these theoretically significant linkages rather than by the more superficial features that initially guided them.
Six-month olds, for instance, fail to search for objects that are hidden behind screens, and they show no surprise when an object moves behind a screen, fails to appear at a gap in the middle of the screen, but then appears whole from behind the other side of the screen.
These behaviors only emerge at 9 months. This in turn strengthens the analogy between cognitive development and active theorizing by adult scientists. Theories and explanatory knowledge are required to focus on the relevant features of categories in a variety of tasks and contexts.
Research with adults has tended to support this perspective. The effect is the tendency of participants to privilege causally deeper or more central properties in a range of tasks including categorization and similarity judgment.
For example, if people are taught about a person who has a cough caused by a certain kind of virus, and then given two other descriptions, one which matches in the cause same virus but not the effect runny nose , and another that matches in the effect cough but not the cause different virus , common causal features make exemplars more similar. Matching causal features can even override other shared features in categorization.
If taught about an example with a cause that produces two effect features and two other examples, one of which shares the cause only and the other of which shares both effects, a majority of participants group the common cause exemplar with the original, even though they differ in most features. Murphy reviews an extensive body of evidence showing that background knowledge has a pervasive effect on category learning, categorization, and induction.
To take two examples, consider artificial category learning and category construction. In learning studies, participants are given two categories that are distinguished by different lists of features. Participants found the coherent categories much easier to learn, and retained more information about them.
Similarly, if given the ability to freely sort these items into categories they tended to group the coherent category members together even when they shared only a single feature.
Background knowledge concerning the likely relationships among these features plays an essential role in learning and categorizing, even when it is not explicitly brought up in the experiment itself. These essences need not be actually known, but may be believed to exist even in the absence of detailed information about them.
Commitment to essences may be viewed as a kind of theoretical commitment, insofar as essences are causally potent but unobserved properties that structure and explain observable properties of categories. More generally, it is the commitment to there being a certain kind of causal structure underlying the categories we commonly represent. There is a large body of evidence that supports the psychological essentialist hypothesis Gelman, , ; see Strevens, for criticism.
They are then told that one object of the resembling pair has a certain property and asked to project the property to the third object. By 30 months, children will project properties on the basis of labeled category membership rather than similarity. This effect does not depend on the precise repetition of the verbal label that is, synonyms work just as well , and it tends to be more powerful in natural biological kinds than in artifacts.
Even among to month olds one can find similar effects: behaviors displayed with one sort of toy animal barking, chewing on a bone, and so forth.
This suggests that induction is not entirely governed by superficial properties even among very young children. Children may entertain more specific hypotheses about what the underlying category essences are as well. Removing outsides or changing a transitory property has little effect on membership or function. These studies provide further evidence that the Original Sim has at best a weak grip on young children.
Moreover, they reinforce the claim that categorization can sometimes be dominated by an early-emerging understanding of biology that treats stereotypical properties as non-dispositive. Whatever the status of these additional claims, the broader moral of the essentialism literature is in line with the proposals made by Theory theorists.
Children come prepared to learn about deeper causal relations in many domains and they readily treat these relations as important in categorizing and making inductions. In recent years much attention has focused on the role of causality in cognition, and consequently theories of cognitive performance that emphasize causal modeling have gained prominence.
The idea that concepts might be identified at least in part with causal models has grown out of this tradition. Briefly, a causal model of a category depicts part of the relevant causal information about how things in the domain are produced, organized, and function. A causal model of a bird notes that it has wings, a body, and feathers, but also encodes the fact that those features causally contribute to its being able to fly; a causal model of a car depicts the fact that it is drivable in virtue of having wheels and an engine, that it can transport people because it is drivable, and that it makes noise because of its engine.
These structures can be represented as sets of features connected by arrows, which indicate when the presence of one property causes or sustains and therefore makes more probable the presence of another. These directed causal graphs provide one possible representational format for concepts. On H I P E, artifact concepts are miniature causal models of the relations among these properties, all of which may potentially contribute to making something the kind of artifact that it is.
Similar sorts of models could be developed for natural kind concepts. Causal model theory is a generalization of this idea that allows these graphs to take many different forms.
While it is tied to a more specific hypothesis about representation than Theory-Theory in general the formalism of directed causal graphs , this is also a strength, since these models are part of a well-developed framework for learning and processing. Causal model theory gives the Theory-Theory the resources to develop more wide-ranging and detailed empirical predictions concerning categorization, induction, and naming.
It is also worth noting that causal model theory may give the concepts as theories view the resources to answer the mereological objection it faces. The components of causal models can be seen as features representing properties, connected by links representing causal relations. Many models of concepts take them to be complex structures composed of features in this way.
If we see causal models as miniature theories, then we can view concepts as theories if we identify them with such models. Adopting this approach eliminates any potential problems about concepts being both the constituents of beliefs and also being composed of beliefs.
The holism objection focuses on the fact that the individuation conditions for concepts are closely tied to those for theories. This gives rise to problems concerning the stability of concepts. The objection may be put as follows. Suppose concepts are identified by their relation to theories.
Then changes in theories entail changes in concepts: if C 1 ,…,C n are constituted by their relation to T 1 , and T 1 changes into T 2 , then at least some of C 1 ,…,C n will have to change as well, so long as the changes in the theories occurs in the parts that contribute to individuating those concepts. And it is part of the developmental and dynamical account of the Theory-Theory that such transitions in theories take place.
So according to the Theory-Theory, concepts are unstable; they change over time, so that one does not have the same concepts before a revision in theory that one has afterwards.
The conclusion is particularly objectionable if one assumes that there will be many changes to theories, so that concepts also change frequently. But there are reasons to want concepts to be more stable than this.
First, one wants to be able to compare concepts across individuals with different theories. A young child may not have the fully developed life concept, but she and I can still have many common beliefs about particular living things and their behavior, even if she does not represent them as being alive in the way that I do that is, even if her understanding of life is impoverished relative to mine.
So now that I believe T 2, I reject B. So we are at a loss to describe the rational nature of the transition between theories. Some sort of independence from belief is required. The problem is that concepts are individuated by their roles, which in turn are determined by the causal, inferential, and evidential roles of the propositions that contain them, and these are precisely what change as theories do Fodor, ; Margolis, This problem faces both the strong concepts in theories view and the concepts as theories view, but the weak concepts in theories view is immune to it, since it allows that concepts may participate in theories without being individuated by them.
Two responses to the holism objection are typical. It is, they suggest, not implausible that young children are to a certain degree incomprehensible to adults, as would be predicted if their world view is incommensurable with ours Carey, , p. Second, others have attempted to avoid this conclusion by distinguishing respects in which concepts may change such as narrow content or internal conceptual role and respects in which they may remain stable such as wide content or reference.
This dual-factor approach is also adopted by Carey The unstable respects are those that differ with background theories, while the stable respects provide continuity so that concepts can be identified across changes and differences in view. The success of this approach depends on whether the stable respects can do the relevant explanatory work needed in psychological explanation and communication. A representational system is compositional if the properties of complex symbols are completely determined by the properties of the simpler symbols that make them up, plus the properties of their mode of combination.
Many have argued that thought is compositional as well Fodor, , which entails that the properties of complex concepts derive wholly from the properties of their constituents.
If thought is compositional, and concepts are the constituents of thoughts, then whatever concepts are must also be compositional.
So if concepts are or are individuated by theories, then theories must similarly be compositional. However, there are good reasons to think that theories are not compositional.
A standard example is the concept of pet fish. The fish might come from the theory of folk biology, while pet might derive from a theory of human social behavior since keeping pets is a sociocultural fact about humans.
If the strong concepts in theories view is right, their content is determined by their inferential role in each of these theories. But pet fish has a novel inferential role that is not obviously predictable from those roles taken individually.
Instances of pet fish, for example, are typically thought to live in bowls and feed on flakes, neither of which is true of pets or fish in general. It is therefore not compositional. The same point can be made about the concepts as theories view. Since examples like this can be multiplied indefinitely, the Theory-Theory cannot account for the general compositionality of thought. While many psychologists have simply ignored these concerns, several responses are possible.
Here are two. First, one can divide concepts into two components, a stable compositional element and a non-compositional element Rips, The compositional element might be thought of just as a simple label, while the non-compositional element includes theoretical and prototypical information. One part has the job of accounting for concept combination, the other has the job of accounting for categorization and inductive inference.
Second, one can try to weaken the compositionality requirement. Perhaps concepts are required only to be compositional in principle, not in practice; or else compositionality might be viewed as a fallback strategy to be employed when there is no other information available about the extension of a complex concept Prinz, ; Robbins, Whichever approach one takes, the compositionality objection highlights the fact that while the Theory-Theory has impressive resources for explaining facts about development and concept deployment, concept combination is more challenging to account for.
The scope objection is one that faces nearly every theory of concepts. See "descriptive definition" in Glossary. The list goes on indefinitely: e. These sorts of claims — about beliefs and theories held by animals — are programmatic. At the current level of theory within psycholinguistics, we are unable to state very precisely just what it is for an animal to have a belief. As a matter of fact, we are unable to state with much clarity and conviction what it is for a human being to have a belief.
In a way, the claims that animals can have beliefs and can engage in theorizing are pre-theoretical. They constitute, not the results of well-confirmed theories in psycholinguistics, but rather some of the intuitively grasped data which we would like to see such theories, in due course of their development, accommodate.
Some more recent research see [96], would tend to lower, somewhat, the ages Piaget found for the various stages of mastery of the concept of causality. Nonetheless, his original finding that it takes children several years to acquire the adult's understanding of the concept remains intact.
The metaphor, "skeleton" and "flesh", which Nagel adopts here is not just his own: it is a familiar one which dozens of other philosophers of science have appropriated as well. Incidentally, there are a few well-known, widely read, philosophers all bearing the name "Nagel". I am here writing of Ernest Nagel. Neither "contextualist" nor "ordinary-language" are particularly good descriptions of the analytic philosophers who are not formalists. A more apt, but even less explanatory, description would be simply "non-formalist".
Very crudely, the non-formalists put more stock into trying to incorporate into their analyses of concepts something of the contextdependency of their uses and the intentions of their users, i. It is a fascinating, and eye-opening, investigation to compare the writings of a formalist on the topic of time see e.
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