What do mechanisms mean

Compare dynamism def. We could talk until we're blue in the face about this quiz on words for the color "blue," but we think you should take the quiz and find out if you're a whiz at these colorful terms. Words related to mechanism instrument , structure , system , tool , agency , operation , procedure , process , technique , apparatus , appliance , components , contrivance , doohickey , gadget , gears , gimmick , innards , machinery , motor. How to use mechanism in a sentence Other candidates, like the one from the American firm Novavax, use a protein-based mechanism.

Dubner August 27, Freakonomics. Are You Yoda or Darth Vader? Is Economic Growth the Wrong Goal? Dubner August 13, Freakonomics. Invention Bradley A. A machine or mechanical appliance. The arrangement of connected parts in a machine. He turned the bowls on their sides and added a pedal mechanism to spin them. There's a real mechanism where you can calculate it. If either of you engage in negative defense mechanisms when attempting to solve a problem, you are building more problems and solving nothing.

It is your body's natural weight control mechanism. For frozen bacteria to survive an exponentially longer period, a related mechanism must be at work. From TIME. I think this is just another mechanism for people making purchases. From CBS News. They are speculating that a virus spread and the human population size crashed, and then adapted by changing their suppression mechanisms.

From National Geographic. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. Collocations with mechanism. Click on a collocation to see more examples of it. From the Cambridge English Corpus.

See all collocations with mechanism. Translations of mechanism in Chinese Traditional. See more. Need a translator? Translator tool. What is the pronunciation of mechanism? Browse mechanical wave BETA. Test your vocabulary with our fun image quizzes. Image credits. In such cases, the phenomenon might be an object the production of a protein , a state of affairs being phosphorylated , or an activity or event such as digestion.

For many physiological mechanisms, in contrast, it is more appropriate to say that the mechanism underlies the phenomenon. The mechanism of the action potential or of working memory, for example, underlies the phenomenon, here characteristically understood as a capacity or behavior of the mechanism as a whole.

Finally, a mechanism might maintain a phenomenon, as when homeostatic mechanisms hold body temperature within tightly circumscribed boundaries. In such cases, the phenomenon is a state of affairs, or perhaps a range of states of affairs, that is held in place by the mechanism.

These ways of talking can in many cases be inter-translated e. Yet clearly confusion can arise from mixing these ways of talking. Must the relationship between the mechanism and the phenomenon be regular? This is an area of active discussion DesAutels ; Andersen , a,b; Krickel Some have understood this incorrectly in our view as asserting that there are no mechanisms that work only once, or that a mechanism must work significantly more than once in order to count as a mechanism.

Some argue that mechanisms have to be regular in this factual sense Andersen a,b ; i. This view would seem to require a somewhat arbitrary cut-off point in degree of regularity between things that truly count as mechanisms and those that do not. Other mechanists argue that the type-token distinction is too crude a dichotomy to capture the many levels of abstraction at which mechanism types and tokens might be characterized Darden While the MDC account leaves open the possibility that some mechanisms are stochastic, it clearly rules out mechanisms that usually fail to produce their phenomena.

Skipper and Millstein press this point to argue that the MDC account cannot accommodate the idea that natural selection is a mechanism. If, as Gould argued, one could not reproduce the history of life by rewinding the tapes and letting things play forward again, then natural selection would not be an MDC mechanism see also Section 2. It is unclear why MDC would allow for the possibility of stochastic mechanisms and rule out, by definition, the possibility that they might fail more often than they work.

Whether any biological mechanisms are truly irregular in this sense i. Krickel reviews the many different ways of unpacking the relevant notion of regularity see also Andersen Mechanists have struggled to find a concise way to express the idea of parthood required of the components in a mechanism. The project is to develop an account that is both sufficiently permissive to include the paradigmatic mechanisms from diverse areas of science and yet not vacuous. Formal mereologies are difficult to apply to the material parts of biological mechanisms.

The parts of mechanisms must have a kind of robustness and reality apart from their place within that mechanism. It should in principle be possible to take the part out of the mechanism and consider its properties in another context. Yet even this is perhaps too strong, given that some parts of a mechanism might become unstable when removed from their mechanistic context. Later, Glennan S says that the properties of a part must be stable in the absence of interventions, or that parts must be stable enough to be called objects.

This notion is perhaps too strong to accommodate the more ephemeral parts of some biochemical mechanisms or of the mechanisms of natural selection Skipper and Millstein ; but see Illari and Williamson Mechanists have disagreed with one another about how to understand the cause in causal mechanism. Four ways of unpacking the cause in causal mechanism have been discussed: conserved quantity accounts, mechanistic accounts, activities accounts, and counterfactual accounts.

It should be noted that some mechanists have evolved in their thinking about causation. According to transmission accounts, causation involves the transmission and propagation of marks or conserved quantities Salmon , ; Dowe The most influential form of this view holds that two causal processes causally interact when they intersect in space-time and exchange some amount of a conserved quantity, such as mass.

On this view, causation is local the processes must intersect and singular it is fully instantiated in particular causal processes , though the account relies upon laws of conservation Hitchcock Although this view inspired many of the new mechanists, and although it shares their commitment to looking toward science for an account of causation, it has generally been rejected by new mechanists though see Millstein ; Roe This view has been unpopular in part because it has little direct application in nonfundamental sciences, such as biology.

Furthermore, biological mechanisms often involve causation by omission, prevention, and double prevention that is, when a mechanism works by removing a cause, preventing a cause, or inhibiting an inhibitor Schaffer , Such forms of causal disconnection are ubiquitous in the special sciences. Glennan , sees causation at least non-fundamental causation as derivative from the concept of mechanism: causal claims are claims about the existence of a mechanism. The truth-maker for a causal claim at one level of organization is a mechanism at a lower level.

In short, mechanisms are the hidden connexion Hume sought between cause and effect. This view has been charged with circularity: the concept of mechanism ineliminably contains a causal element. Furthermore, he argues that for at least all non-fundamental causes, a mechanisms clearly explains how a given cause produces its effect.

Whether the analysis succeeds depends on how one deals with the resulting regress Craver As Glennan notes, the decomposition of causes into mechanisms might continue infinitely, in which case there is no point arguing about which notion is more fundamental, or the decomposition might ground out in some basic, lowest-level causal notion that is primitive and so not analyzable into other causal mechanisms.

The latter option must confront the widely touted absence of causation in the theories of fundamental physics Russell ; at very small size scales, classical conceptions of objects and properties no longer seem to apply, making it difficult to see what content is left to the idea that there are mechanisms at work see also Teller ; Kuhlman and Glennan Still other mechanists, such as Bogen , a and Machamer Machamer , embrace an Anscombian, non-reductive view that causation should be understood in terms of productive activities see also the entry on G.

Activities are kinds of causing, such as magnetic attraction and repulsion or hydrogen bonding. Defenders of activity-based accounts eschew the need to define the concept, relying on science to say what activities are and what features they might have. This view is a kind of causal minimalism Godfrey-Smith Whether an activity occurs is not a matter of how frequently it occurs or whether it would occur always or for the most part in the same conditions Bogen This account has been criticized as vacuous because it fails to say what activities are Psillos , to account for the relationship of causal and explanatory relevance Woodward , and to mark an adequate distinction between activities and correlations Psillos , though see Bogen , a for a response.

Glennan forthcoming argues that these problems can be addressed by recognizing that activities in a mechanism at one level depend on lower-level mechanisms. See also Persson for a criticism of activities based on their inability to handle cases of polygenic effects. Lastly, some new mechanists, particularly those interested in providing an account of scientific explanation, have gravitated toward a counterfactual view of causal relevance, and in particular, to the manipulationist view expressed in Woodward , see, e.

The central commitment of this view is that models of mechanisms describe variables that make a difference to the values of other variables in the model and to the phenomenon. Difference-making in this manipulationist sense is understood as a relationship between variables in which interventions on cause variables can be used to change the value of effect variables see the entry on causation and manipulability. Unlike the views discussed above, this way of thinking about causation provides a ready analysis of explanatory relevance that comports well with the methods for testing causal claims.

Roughly, one variable is causally relevant to a second when there exists an ideal intervention on the first that changes the value of the second via the change induced on the first. The view readily accommodates omissions, preventions, and double preventions—situations that have traditionally proven troublesome for production-type accounts of causation. In short, the claim that C causes E requires only that ideal interventions on C can be used to change the value of E , not that C and E are physically connected to one another.

Finally, this view provides some tools for accommodating higher-level causal relations and the non-accidental laws of biology. On the other hand, the counterfactual account is non-reductive like the mechanistic view , and it inherits challenges faced by other counterfactual views, such as pre-emption and over-determination which are common in biological mechanisms see the entry on counterfactual theories of causation.

Wimsatt contrasts mechanistic organization with aggregation, a distinction that mechanists have used to articulate how the parts of a mechanism are organized together to form a whole see Craver b. Aggregate properties are properties of wholes that are simple sums of the properties of their parts. In aggregates, the parts can be rearranged and intersubstituted for one another without changing the property or behavior of the whole, the whole can be taken apart and put back together without disrupting the property or behavior of the whole, and the property of the whole changes only linearly with the addition and removal of parts.

These features of aggregates hold because organization is irrelevant to the property of the whole. Wimsatt thus conceives organization as non-aggregativity. He also describes it as a mechanistic form of emergence see Section 4.

Mechanistic emergence is ubiquitous—truly aggregative properties are rare. Thus mechanists have tended to recognize a spectrum of organization, with aggregates at one end and highly organized mechanisms on the other. Indeed, many mechanisms studied by biologists involve parts and causings all across this spectrum.

For further discussion of mechanistic emergence in relationship to other varieties, see Richardson and Stephan Following Wimsatt, mechanists have detailed several kinds of organization characteristic of mechanisms. A canonical list includes both spatial and temporal organization. Spatial organization includes location, size, shape, position, and orientation; temporal organization includes the order, rate, and duration of the component activities.

More recently, mechanists have emphasized organizational patterns in mechanisms as a whole. Bechtel, for example, discusses how mathematical models, and dynamical models in particular, are used to reveal complex temporal organization in interactive mechanisms Bechtel , , b.

Some argue that dynamical models push beyond the limits of the mechanistic framework e. Others argue that dynamical models are, in fact, often merely descriptive i. Understanding how parts compose wholes is likely to be a growth area in the future of the mechanistic framework. For some other recent additions, see Kuorikoski and Ylikoski ; Kuhlmann ; Glennan forthcoming. This means, roughly, that it should be physically possible to intervene on a putative cause variable in a mechanism without disrupting the functional relationships among the other variables in the mechanism.

In terms of structural equation models in particular, this means that one should be able to replace the right-hand side of an equation in the model with a particular value i. This is intended to formally capture the sense in which mechanism is composed of separable, interacting parts.

For arguments in favor of a modularity condition on mechanistic models see Menzies Grush , following Haugeland , develops an idea of modularity in terms of the bandwidth of interaction, where modules are high-bandwidth in their internal interactions and low-bandwidth in their external interactions. On this view, modularity is not an all-or-none proposition but a matter of degree; mechanisms are only nearly decomposable. Craver argues that such a generic notion fails to account for the relevance of different causal interactions for different mechanistic decompositions; what counts as a part of a mechanism can only be defined relative to some prior decision about what one takes the mechanism to be doing.

For criticisms of modularity, see Mitchell and Cartwright , Fagan , emphasizes the interdependent relationship between parts of a mechanism. This interdependent relationship—jointness—is exemplified by the lock-and-key model of enzyme action. Fagan applies this notion to research on stem cells Fagan but argues that it is a general feature of experimental biology Fagan Many mechanists emphasize the hierarchical organization of mechanisms and the multilevel structure of theories in the special sciences see especially Craver , Ch.

Antecedents of the new mechanism focused almost exclusively on etiological, causal relations. However, the new emphasis on mechanisms in biology and the special sciences demanded an analysis of mechanistic relations across levels of organization.

From a mechanistic perspective, levels are not monolithic divides in the furniture of the universe as represented by Oppenheim and Putnam , nor are they fundamentally a matter of size or the exclusivity of causal interactions within a level Wimsatt Rather, levels of mechanisms are defined locally within a multilevel mechanism: one item is at a lower level of mechanisms than another when the first item is a part of the second and when the first item is organized spatially, temporally, and actively with the other components such that together they realize the second item.

Thus, the mechanism of spatial memory has multiple levels, some of which include organs such as the hippocampus generating a spatial map, some of which involve the cellular interactions that underlie map generation, and some of which involve the molecular mechanisms that underlie those cellular interactions Craver For more on levels, see Section 4. Finally, mechanists have found it necessary to distinguish between stable mechanisms, which rely fundamentally upon the more or less fixed arrangement of parts and activities, and ephemeral mechanisms, which involve a process evolving through time without fixed spatial and temporal arrangement Glennan The time-keeping mechanism in a clock, for example, is a relatively stable assemblage of components in relatively fixed locations that work the same way, with the same organizational features, each time it works.

Ephemeral mechanisms, in contrast, involve a much looser kind of organization: items still interact in space and time, but they do not do so in virtue of robust, stable structures. Many chemical mechanisms in a cell are like that Richardson and Stephan Ephemeral mechanisms are surely a primary focus of historical sciences, such as archaeology, history, and evolutionary biology Glennan Here, we first distinguish the new mechanism from other doctrines with which it shares both name and family resemblance.

The idea of mechanism is a central part of the explanatory ideal of understanding the world by learning its causal structure. The history of science contains many other conceptions of scientific explanation and understanding that are at odds with this commitment. Some have held that the world should be understood in terms of divine motives. Some have held that natural phenomena should be understood teleologically.

Others have been convinced that understanding the natural world is nothing more than being able to predict its behavior. Commitment to mechanism as a framework concept is commitment to something distinct from and, for many, exclusive of, these alternative conceptions. If this appears trivial, rather than a central achievement in the history of science, it is because the mechanistic perspective now so thoroughly dominates our scientific worldview.

Yet there are many ways of organizing phenomena besides revealing mechanisms. Some scientists are concerned with physical structures and their spatial relations without regard to how they work: an anatomist might be interested in the spatial organization of parts within the body with minimal interest in how those parts articulate together to do something.

Many scientists build predictive models of systems without any pretense that these models in fact reveal the causal structures by which the systems work. Some scientists are concerned with taxonomy, sorting like with like without regard to how the sorted items came about or how they work. Finally, in many areas of science, there is a widely recognized and practically significant distinction between knowing that C e.

In short, there are many framework concepts in science, and not all of them can be assimilated to mechanisms. But what, the critic might push further, does not count as a mechanism?

Here are some contrast classes:. This is not an exhaustive list of non-mechanisms or non-mechanistic framework concepts.

Yet it demonstrates that even the liberalized concept of mechanism is neither vacuous nor trivial. Much of the early new mechanical philosophy has focused on the special sciences, such as neuroscience and molecular biology. In the years since, philosophers have extended the mechanistic framework to other scientific disciplines, such as cell biology Bechtel , cognitive science Bechtel ; Thagard , neuroeconomics Craver and Alexandrova , organic chemistry Ramsey , physics Teller , astrophysics Illari and Williamson , behavior genetics Tabery a , and phylogenetics Matthews forthcoming.

Philosophers continue to test the limits of this framework, with the expectation that alternative organizing frameworks might play central roles in other sciences. For example, a debate has emerged in the philosophy of biology over whether or not natural selection is a mechanism see, for example, Skipper and Millstein ; Baker ; Barros ; Illari and Williamson ; Havstad ; and Matthewson and Calcott Similar debates have emerged concerning mechanistic explanation in cognitive science Bechtel ; Piccinini and Craver ; Weiskopf ; Povich forthcoming.

One area that has received particular attention is the effort to understand computational mechanisms. On some accounts, computational mechanisms form a proper subclass of mechanisms that can be defined explicitly in terms of the kinds of entities, properties, and activities involved in mechanisms in that class Piccinini ; Milkowski According to this view, computational mechanisms are mechanisms that have the function to manipulate medium independent vehicles in accordance with a general rule that applies to all vehicles and depends on the inputs for its application Piccinini and Scarantino Digital computers are distinctive in that their vehicles are digits Piccinini Proponents of this account hope to demarcate computing mechanisms from non-computing mechanisms by appeal to the distinctive components proprietary to computing mechanisms.

This view contrasts both with a semantic view, according to which computation is essentially a matter of manipulating symbols or representations, and with perspectivalist views, according to which whether a mechanism counts as computing is a matter of whether it is so described Churchland ; Churchland and Sejnowski ; Shagrir Philosophers of the social sciences have also emphasized and debated the importance of mechanistic knowledge e.

In that context, appeals to mechanisms are intended to remedy the relative uninformativeness of social or macro-level explanations of social phenomena such as widespread norms, persistent inequalities, network and institutional structures by insisting that these explanations ultimately be grounded in mechanistic details about individual agents and actors, their desires and motivations, and, importantly, their relations to one another.

The emphasis on relations among actors distances this mechanistic view from methodological individualism see the entry on methodological individualism. Mechanists in the social sciences have also tended to shy away from grand, overarching theories and toward more local explanations: scientific knowledge grows by adding items to a toolbox of mechanisms and showing how items from that toolbox can be combined to provide an explanation for a particular phenomenon.

The covering-law model of explanation was a centerpiece of the logical empiricist conception of science. According to that model, explanations are arguments showing that the event to be explained the explanandum event was to have been expected on the basis of laws of nature and the antecedent and boundary conditions the explanans.

For advocates of the covering-law model, the philosophical problem of explanation is thus largely a matter of analyzing the formal structure of explanatory arguments Hempel and Oppenheim ; Hempel A rainbow, for example, is explained under the covering-law model by reference to laws of reflection and refraction alongside conditions concerning the position of the sun and the nature of light, the position of the raindrops, and the position of the person seeing the rainbow.

The description of the rainbow is the conclusion of a deductive argument with law statements and descriptions of conditions as premises, and so the rainbow was to be expected in light of knowledge of the laws and conditions. Mechanists, in contrast, insist explanation is a matter of elucidating the causal structures that produce, underlie, or maintain the phenomenon of interest. For mechanists, the philosophical problem is largely about characterizing or describing the worldly or ontic structures to which explanatory models including arguments must refer if they are to count as genuinely explanatory.

A rainbow, for the mechanist, is explained by situating that phenomenon in the causal structure of the world; the explanation is an account of how the phenomenon was produced by entities like rain drops and eyeballs with particular properties like shapes and refractive indices that causally interact with light propagating from the sun. Mechanists typically distinguish several ways of situating a phenomenon within the causal structure of the world.

Most mechanists recognize two main aspects of mechanistic explanation: etiological and constitutive. Salmon describes them as two different ways of situating an explanandum phenomenon in the causal nexus see also Craver b; Glennan Etiological explanations reveal the causal history of the explanandum phenomenon, as when one says a virus explains a disease. Constitutive explanations, in contrast, explain a phenomenon by describing the mechanism that underlies it, as when one says brain regions, muscles, and joints explain reaching.

Philosophical arguments against the covering law model often focused on its inability to deal with causal, etiological explanations. The model failed to deliver the right verdict on a variety of problem cases precisely because it attempted to provide an account of explanation without any explicit mention of causation Bromberger ; Salmon ; Scriven New mechanists extend these kinds of criticism to the covering law model of intertheoretic, micro-reduction. According to the covering law model of reductive explanation, a theory about parts reduces, and so explains, a theory about wholes when it is possible to derive the second from the first given bridge laws to connect the two see Nagel ; Schaffner Some mechanists argue that the covering law model of constitutive explanation has problems analogous to those that beset the covering-law model of etiological explanations.

Action potentials cannot be explained by mere temporal sequences of events utterly irrelevant to the phenomenon, but one can derive a description of the action potential from descriptions of such irrelevant phenomena. Action potentials cannot be explained by mere patterns of correlation that are not indicative of an underlying causal relation. Irrelevant byproducts of a mechanism might be correlated with the behavior of the mechanism, even perfectly correlated such that one could form bridge laws between levels, but would not thereby explain the relationship.

Merely finding a neural correlate of consciousness, for example, would not, and is not taken by anyone to, constitute an explanation of consciousness. So mechanists argue that micro-reductive explanations must satisfy causal constraints just as surely as etiological explanations must Craver The covering law model also fails to distinguish models that merely re-describe the phenomenon in general terms from explanations that, in addition to predicting aspects of the phenomenon, reveal the mechanisms that produce it Craver ; Kaplan and Craver ; but see Weiskopf New mechanists also argue that the covering law model fails to distinguish predictively adequate but fictional models from explanatory models.

Finally, mechanists argue that the intertheoretic model of reduction fails to capture an important dimension of explanatory quality: depth. An implication of the covering law model is that any true law statements that allow one to derive the explanandum law with suitable corrections and assumptions will count as a complete explanation. Yet it seems one can deepen an explanation by opening black boxes and revealing how things work down to whatever level one takes as relatively fundamental for the purposes at hand.

Such criticisms suggest that the covering-law model of constitutive explanation is too weak to capture the norms of explanation in the special sciences. Other mechanists have argued that the covering law model is too strong. Philosophers of biology have long argued that there are no laws of the sort the logical empiricist described in biology and other special sciences Beatty ; Mitchell , ; Woodward One might conclude from this that there are no explanations in biology Rosenberg , but such a radical conclusion is difficult to square with obvious advances in understanding, e.

In such cases, one finds that scientists appeal to mechanisms to do the explanatory work, even in cases where nothing resembling a law appears to be available. With increased attention to constitutive explanation, mechanists realized the need for an account of constitutive relevance, a principal for sorting relevant from irrelevant factors in a mechanism Craver ; Ylikoski One central research problem is to say which of these entities, activities, and organizational features contribute to the phenomenon and which do not.

In a sense, this is a challenge of defining the boundaries of a mechanism: of saying what is and is not in the mechanism. Three proposals have been considered.

The first, the mutual manipulability account , understands constitutive relevance in terms of the experimental manipulations used to test interlevel relations. A concern with the mutual manipulability account, though, is that it is best an epistemic guide to constitutive relevance, not an account of what constitutive relevance is Couch The account offers, at best, a sufficient condition of relevance.

An ideal intervention on a system cannot intervene on both the independent and the dependent variable at the same time. On this account, a constitutively relevant component is an insufficient but non-redundant part of an unnecessary but sufficient mechanism for a given phenomenon Couch ; see also Harbecke , A third approach to constitutive relevance dispenses with the interlevel framing enforced by the mutual manipulability account and attempts to analyze relevance using causal notions only.

According to accounts of this sort, constitutive relevance is a kind of causal between-ness. The putatively interlevel experiments in the mutual manipulability account can then be recast as different kinds of unilevel causal experiments. Romero forthcoming provides a helpful framing of these issues and offers the novel suggestion that putatively high-level interventions are in fact fat-handed interventions relative to their lower-level counterparts.

The philosophical literature on mechanisms also overlaps with the philosophical literature on scientific models see the entry on models in science. Here we distinguish mechanical models from models of mechanisms and we discuss varieties of non-mechanical models. Such models can be represented in many different ways see also Giere They are evaluated in terms of their ability to predict the features of the phenomenon and in terms of the mapping between items in the model and the entities, activities, and organizational features in the mechanism Glennan 17; Kaplan and Craver Glennan emphasizes that there is no hard line between complete and incomplete models; rather models are continually in the process of articulation and refinement.

Whether a model is complete enough is determined by pragmatic considerations. While no model is ever complete in the absolute sense, some models have lacunae that must be filled before the model is complete enough.

Mechanism schemas are abstract descriptions of mechanisms that can be filled in with details to yield a specific type or token mechanism. Thus, the schema:. The arrows can be filled in, showing how transcription and translation work. A mechanism sketch is an incomplete representation of a mechanism that specifies some of the relevant entities, activities, and organizational features but leaves gaps that cannot yet be filled. Mechanists also emphasize the distinction between a how-possibly schema and a how-actually-enough schema Craver and Darden A how-possibly schema describes how entities and activities might be organized to produce a phenomenon.

A how possibly model is n hypothesis about how the mechanism works. Such models might be true enough or false. A true enough how-possibly model is though we may not know it also a how-actually enough model. A how-actually-enough schema describes how entities and activities are in fact organized to produce the phenomenon.

A false how possibly model is merely a how possibly model; just-so-stories are merely how possibly models Dray ; Brandon In contrast to mechanism schemas and sketches, some models of mechanisms work not by describing all of the parts, causal interactions, and organizational features, but rather by abstracting away from such potentially obfuscating details Craver and Darden ; Strevens ; Levy and Bechtel In such cases, idealizing assumptions can be introduced to bring the relevant feature of the mechanism most clearly into view: infinite populations, frictionless planes, perfect geometrical shapes are presumed in order to strip the model of detail that does not matter for, or would only obstruct, the intended purposes of model.

Critics of the new mechanical philosophy have pushed on the importance of abstraction in science, drawing attention to the above discussions of completeness. The goals of completeness and accuracy are taken to conflict with the common practice of being satisfied with models that sacrifice detail and truth for clarity and generality Strevens ; Woodward The normative distinction between a schema and a sketch, for example, seems to suggest that science progresses by moving from incomplete to complete models.

And the distinction between how-possibly and how-actually-enough likewise seems to privilege accuracy over other goals of modeling, which often require distortion and falsity see Wimsatt ; Weisberg ; Levy and Bechtel ; Batterman and Rice ; Chirimuuta ; Levy