Functionalism, Misc

The empirical study of belief is emerging at a rapid clip, uniting work from all corners of cognitive science. Reliance on belief in understanding and predicting behavior is widespread. Examples can be found, inter alia, in the placebo, attribution theory, theory of mind, and comparative psychological literatures. Research on belief also provides evidence for robust generalizations, including about how we fix, store, and change our beliefs. Evidence supports the existence of a Spinozan system of belief fixation: one that is automatic (...) and independent of belief rejection. Independent research supports the existence of a system of fragmented belief storage: one that relies on large numbers of causally isolated, context-sensitive stores of belief in memory. Finally, empirical and observational data support at least two systems of belief change. One system adheres, mostly, to epistemological norms of updating; the other, the psychological immune system, functions to guard our most centrally held beliefs from potential inconsistency with newly formed beliefs. Refining our under- standing of these systems can shed light on pressing real-world issues, such as how fake news, propaganda, and brainwashing exploit our psychology of belief, and how best to construct our modern informational world. (shrink)

According to pure imperativism, pain experiences are experiences of a specific phenomenal type that are entirely constituted by imperative content. As their primary argument, proponents of imperativism rely on the biological role that pain experiences fulfill, namely, the motivation of actions whose execution ensures the normal functioning of the body. In the paper, I investigate which specific types of action are of relevance for an imperative interpretation and how close their link to pain experiences actually is. I argue that, although (...) imperative theories constitute an apparently promising version of strong intentionalism, they cannot provide an imperative content that meets their own criteria of both sufficiency and necessity. I further argue that this issue cannot be solved by impure imperative theories either. (shrink)

Whole Brain Emulation has been championed as the most promising, well-defined route to achieving both human-level artificial intelligence and superintelligence. It has even been touted as a viable route to achieving immortality through brain uploading. WBE is not a fringe theory: the doctrine of Computationalism in philosophy of mind lends credence to the in-principle feasibility of the idea, and the standing of the Human Connectome Project makes it appear to be feasible in practice. Computationalism is a popular, independently plausible theory, (...) and Connectomics a well-funded empirical research program, so optimism about WBE is understandable. However, this optimism may be misplaced. This article argues that WBE is, at best, no more compelling than any of the other far-flung routes to achieving superintelligence. Similarly skeptical conclusions are found regarding immortality. The essay concludes with some positive considerations in favor of the Biological Theory of consciousness, as well as morals about the limits of Computationalism in both artificial intelligence and the philosophy of mind more generally. (shrink)

In this essay, I propose a functionalist theory of grounding (functionalist-grounding). Specifically, I argue that grounding is a second-order phenomenon that is realized by relations that play the noncausal explanatoriness role. I also show that functionalist-grounding can deal with a powerful challenge. Appeals to explanatory unificationism have been made to argue that the success of noncausal explanations does not depend on the existence of grounding relations. Against this, I argue that a systematization involving functionalist-grounding is superior to its anti-relational counterpart.

Ramsification is a well-known method of defining theoretical terms that figures centrally in a wide range of debates in metaphysics. Prior's puzzle is the puzzle of why, given the assumption that that-clauses denote propositions, substitution of "the proposition that P" for "that P" within the complements of many propositional attitude verbs sometimes fails to preserve truth, and other times fails to preserve grammaticality. On the surface, Ramsification and Prior's puzzle appear to have little to do with each other. But Prior's (...) puzzle is much more general than is ordinarily appreciated, and Ramsification requires a solution to the generalized form of Prior's puzzle. Without such a solution, a wide range of theories will either fail to imply their Ramsey sentences, or have Ramsey sentences that are ill-formed. As a consequence, definitions of theoretical terms given using the Ramsey sentence will be either incorrect or nonsensical. I present a partial solution to the puzzle that requires making use of a neo-Davidsonian language for scientific theorizing, but the would-be Ramsifier still faces serious challenges. (shrink)

According to noncognitivism, normative beliefs are just desire-like attitudes. While noncognitivists have devoted great effort to explaining the nature of normative belief, they have said little about all of the other attitudes we take towards normative matters. Many of us desire to do the right thing. We sometimes wonder whether our conduct is morally permissible; we hope that it is, and occasionally fear that it is not. This gives rise to what Schroeder calls the 'Many Attitudes Problem': the problem of (...) developing a plausible noncognitivist account of the full range of attitudes that we take towards normative matters. This paper explores the problem and proposes a solution. (shrink)

The extended mind thesis claims that some mental states and cognitive processes extend onto the environment. Items external to the organism or exploratory actions may constitute in part mental states and cognitive processes. In Clark and Chalmers’ original paper, ‘The Extended Mind’, this thesis receives support from the parity principle and from the active externalism. In their paper, more emphasis is given to the parity principle, which is presented as neutral regarding the nature of cognition. It would be advantageous to (...) maintain that extended mental states and processes do not require a reform of our pre-theoretical view of cognition. In the present paper, I submit that we should give more emphasis on the active externalism, which, I argue, is not neutral regarding the nature of cognition. Cognition is viewed as successful adaptation to a specific task. Although this move may seem at first disadvantageous, it is necessary for the correct understanding and justification of Otto case as an example of extended mental state. Additionally, the parity principle cannot handle Weiskopf’s criticism that information registered in Otto’s notebook is not responsive to reasons. In order to address this criticism, we need to appeal to active externalism and its corresponding view of cognition. (shrink)

On the one hand, Aristotle claims that the matter of a material thing is not part of its form. On the other hand, he suggests that the proper account of a natural thing must include a specification of the kind of matter in which it is realized. There are three possible strategies for dealing with this apparent tension. First, there may be two kinds of definition, so that the definition of the form of a thing does not include any specification (...) of its matter, whereas the definition of a compound does. Second, the definition of a substance may not include a specification of its matter at all, but still reveal in what kinds of matter its form can be realized. Third, there may be a special kind of matter, functional matter, which belongs to the form of certain things. I will show that the functional matter of a thing does not belong to its form, but that an adequate account of natural substances and their functions must nonetheless involve a reference to their functional matter. This means that the function of a natural thing is not the same as its form and that its adequate account as a natural thing is not a definition. (shrink)

Two theories dominate the current debate on group agency: functionalism, as endorsed by Bryce Huebner and Brian Epstein, and interpretivism, as defended by Deborah Tollefsen, and Christian List and Philip Pettit. In this paper, I will give a new argument to favour functionalism over interpretivism. I discuss a class of cases which the former, but not the latter, can accommodate. Two features characterise this class: First, distinct groups coincide, that is numerically distinct groups share all their members at all time. (...) Second, we have access to the inner mechanisms of the groups agents, because members know what they have decided on. I construct a counterexample with these features allowing me to reject interpretivism about group agency in favour of functionalism. (shrink)

Extended cognition theorists argue that cognitive processes constitutively depend on resources that are neither organically composed, nor located inside the bodily boundaries of the agent, provided certain conditions on the integration of those processes into the agent’s cognitive architecture are met. Epistemologists, however, worry that in so far as such cognitively integrated processes are epistemically relevant, agents could thus come to enjoy an untoward explosion of knowledge. This paper develops and defends an approach to cognitive integration—cluster-model functionalism—which finds application in (...) both domains of inquiry, and which meets the challenge posed by putative cases of cognitive or epistemic bloat. (shrink)

This paper examines Miranda Fricker’s method of paradigm-based explanation and in particular its promise of yielding an ordered pluralism. Fricker’s starting point is a schism between two conceptions of forgiveness, Moral Justice Forgiveness and Gifted Forgiveness. In the light of a hypothesis about the basic point of forgiveness, she reveals the unity underlying the initially baffling plurality and brings order into it, presenting a paradigmatic form of forgiveness as explanatorily basic and other forms as derivative. The resulting picture, she claims, (...) is an ‘explanatorily satisfying ordered pluralism.’ But what is this ordered pluralism and how does Fricker’s method deliver it? And to what extent can this strategy be generalised to other conceptual practices? By making explicit and critically examining the conception of ordered pluralism implicit in Fricker’s procedure, I assess the promise that her approach holds as a way of resolving stand-offs between warring conceptions of ideas or practices more widely. I argue that it holds great promise in this respect, but that if we are to avoid reproducing just the schismatic debates that the pluralism of paradigm-based explanation is supposed to overcome at the level of what is to be regarded as a paradigm case, we need to take seriously the thought that what counts as a paradigm is partly determined by our purposes in giving a paradigm-based explanation. (shrink)

In 1956 U. T. Place proposed that consciousness is a brain process. More attention should be paid to his word ‘process’. There is near-universal agreement that experiences are processive—as witnessed in the platitude that experiences are occurrent states. The abandonment of talk of brain processes has benefited functionalism, because a functional state, as it is usually conceived, cannot be a process. This point is dimly recognized in a well-known but little-discussed argument that conscious experiences cannot be functional states because the (...) former are occurrent, while the latter are dispositional. That argument fails, but it can be made sound if we reformulate it with the premise that occurrent states are processive. The only way for functionalists to meet the resulting challenge is to abandon the standard individuation of functional states in terms of purely abstract causal roles. (shrink)

This paper provides some responses to Tom Polger and Larry Shapiro’s The Multiple Realization Book (2016). I first provide a description of the authors’ framework for thinking about multiple realization and the conditions they claim this involves. I explain what I think they get right and what they get wrong with this framework. After this, I then consider a few examples of multiple realization they discuss and the interpretations they offer. While I am sympathetic to several things they say about (...) multiple realization, I also think there are some questions that have yet to be answered. (shrink)

This paper investigates the question of how to correctly capture the scope of singular thinking. The first part of the paper identifies a scope problem for the dominant view of singular thought maintaining that, in order for a thinker to have a singular thought about an object o, the thinker has to bear a special epistemic relation to o. The scope problem has it is that this view cannot make sense of the singularity of our thoughts about objects to which (...) we do not or cannot bear any special epistemic relation. The paper focuses on a specific instance of the scope problem by addressing the case of thoughts about the natural numbers. Various possible solutions to the scope problem within the dominant framework are assessed and rejected. The second part of the paper develops a new theory of singular thought which hinges on the contention that the constraints that need to be met in order to think singularly vary depending on the kind of object we are thinking about. This idea is developed in detail by discussing the difference between the somewhat standard case of thoughts about spatio-temporal medium-sized inanimate objects and the case of thoughts about the natural numbers. It is contended that this new Pluralist theory of singular thought can successfully solve the scope problem. (shrink)

Triviality arguments against the computational theory of mind claim that computational implementation is trivial and thus does not serve as an adequate metaphysical basis for mental states. It is common to take computational implementation to consist in a mapping from physical states to abstract computational states. In this paper, I propose a novel constraint on the kinds of physical states that can implement computational states, which helps to specify what it is for two physical states to non-trivially implement the same (...) computational state. (shrink)

It is argued that although George Bealer's influential ‘Self-Consciousness argument’ refutes standard versions of reductive functionalism (RF), it fails to generalize in the way Bealer supposes. To wit, he presupposes that any version of RF must take the content of ‘pain’ to be the property of being in pain (and so on), which is expressly rejected in independently motivated versions of conceptual role semantics (CRS). Accordingly, there are independently motivated versions of RF, incorporating CRS, which avoid Bealer's main type of (...) refutation. I focus particularly on one such theory, which takes concepts to be event types that are individuated by their psychological roles, which has the resources of responding to each of the more specific worries Bealer expresses. (shrink)

My primary target in this paper is a puzzle that emerges from the conjunction of several seemingly innocent assumptions in action theory and the metaphysics of moral responsibility. The puzzle I have in mind is this. On one widely held account of moral responsibility, an agent is morally responsible only for those actions or outcomes over which that agent exercises control. Recently, however, some have cited cases where agents appear to be morally responsible without exercising any control. This leads some (...) to abandon the control-based account of responsibility and replace it with an alternative account. It leads others to deny the intuition that agents are responsible in these troublesome cases. After outlining the account of moral responsibility I have in mind, I look at some of the arguments made against the viability of this theory. I show that there are conceptual resources for salvaging the control account, focusing in particular on the nature of vigilance. I also argue that there is empirical data that supports the control account so conceived. (shrink)

The central objection to neo-Lockeanism about persons is the too many thinkers problem: NLP ends up with an absurd multiplication of thinkers. Sydney Shoemaker attempts to solve this problem by arguing that the person and the animal do not share all of the same physical properties. This, according to him, leads to the idea that mental properties are realized in the person’s physical properties only. The project of this paper is to reject Shoemaker’s physicalist solution to the too many thinkers (...) problem. I first argue that his physicalism fails to explain why two physically indistinguishable objects differ in their persistence conditions and physical properties. I then argue that Shoemaker illicitly treats the case of the person and the case of the animal differently, first in regard to cerebral function and its relation to mental properties, and second in regard to brainstem function and its relation to biological properties. This shows that Shoemaker’s solution actually undermines his entire argument. (shrink)

This chapter argues that Simon anticipated what has emerged as the consensus view about human cognition: embodied functionalism. According to embodied functionalism, cognitive processes appear at a distinctively cognitive level; types of cognitive processes (such as proving a theorem) are not identical to kinds of neural processes, because the former can take various physical forms in various individual thinkers. Nevertheless, the distinctive characteristics of such processes — their causal structures — are determined by fine-grained properties shared by various, often especially (...) bodily related, physical processes that realize them. Simon’s apparently anti-embodiment views are surveyed and are shown to be consistent with his many claims that lend themselves to an embodied interpretation and that, to a significant extent, helped to lay the groundwork for an embodied cognitive science. (shrink)

A common view is that the truth of multiple realization—e.g., about psychological states—entails the truth of functionalism. This is supposed to follow because what is multiply realized is eo ipso realized. I argue that view is mistaken by demonstrating how it misrepresents arguments from multiple realization. In particular, it undermines the empirical component of the arguments, and renders the multiplicity of the realization irrelevant. I suggest an alternative reading of multiple realizability arguments, particularly in philosophy of psychology. And I explain (...) the proper way to understand the relation between realization and multiple realization. (shrink)

Starting with Aristotle and moving on to Darwin, Marco Solinas outlines the basic steps from the birth, establishment and later rebirth of the traditional view of living beings, and its overturning by evolutionary revolution. The classic framework devised by Aristotle was still dominant in the 17th Century world of Galileo, Harvey and Ray, and remained hegemonic until the time of Lamarck and Cuvier in the 19th Century. Darwin's breakthrough thus takes on the dimensions of an abandonment of the traditional finalistic (...) theory. It was a transition exemplified in the morphological analysis of useless parts, such as the sightless eyes of moles, already discussed by Aristotle, which Darwin used as a crowbar to unhinge the systematic recourse to final causes. With many excerpts, a chronological sequence and an analytical approach, this book follows the course of the two conceptions that have shaped the destiny of life sciences in western culture. (shrink)

Some philosophers defend the view that epistemic agents believe by lending credence. Others defend the view that such agents lend credence by believing. It can strongly appear that the disagreement between them is notational, that nothing of substance turns on whether we are agents of one sort or the other. But that is demonstrably not so. Only one of these types of epistemic agent, at most, could manifest a human-like configuration of attitudes; and it turns out that not both types (...) of agent are possible. (shrink)

This dissertation aims to examine whether John Searle’s biological naturalism is a more viable alternative to current physicalist and functionalist positions in dealing with the issue of free will. Thus, my strategy is to identify the assumptions of these lines of thought and their philosophical consequences. In order to accomplish this goal the concept of intrinsic intentionality is taken as a guide. I begin by defining what is meant by free will and go on to broadly characterize physicalist and functionalist (...) positions in philosophy of mind. Then, I go on to show how the question of free will arises and can be crucial to such currents of thought. Subsequently, I summarize the biological naturalist position (especially regarding the ontology of consciousness and the question of intentionality) and oppose it to physicalism and functionalism in order to examine the possibility of free will. In this opposition, each theory is decomposed into its main tenets so that they can be critically analyzed. In this analysis, it appears that free will does not seem to find any room in the scenario presented by physicalism and functionalism. It is argued that Searlean biological naturalism is able to explain – better than the other two positions – how free action can be motivated by something that is external to the mental state which is itself performing the action. I then evaluate the ethical implications of these findings, articulating the issues of intrinsic intentionality, free will, strong artificial intelligence in order to conclude that current machines cannot be assigned moral responsibility, since they are not capable of intrinsic intentionality. Then, I argue for the evolutionary origin of intentionality and therefore morality. Finally, I argue that neuroscience does not eliminate moral responsibility since it does not prove that free will is an illusion, i.e., that this branch of science does not contradict John Searle’s biological naturalism. (shrink)

Interview with professor Robert D Rupert.

My aim is to rekindle interest in David Lewis's (1983) infamous but neglected Mixed Theory of mental states. The Mixed Theory is a mix of physicalism and functionalism designed to capture the intuitions that both Martians and abnormal human Madmen can be in pain. The Mixed Theory is widely derided. But I offer a new development of the Mixed Theory immune to its most prominent objections. In doing so, I uncover a new motivation for the Mixed Theory: its unique ability (...) to explain cases in which it is plausibly indeterminate whether something is in pain. The Mixed Theory, whether or not it is ultimately correct, at least deserves renewed attention. (shrink)

Sellars, Brandom, and McDowell (whom Maher aptly calls the “Pittsburgh School”) have tremendous influence on the current shape of the analytic tradition. Despite their differing views on philosophy of language, the philosophy of mind, philosophy of action, and epistemology, their shared application of ‘normative functionalism’ highlights important similarities in their approaches to the aforementioned disciplines. Normative functionalism interprets the ability to form judgments, possess concepts, rationally defend or be critical of judgments, and consequently act as an agent, as largely guided (...) by one’s responsiveness to norms. In this article, I argue for two related claims. First, I argue that the Pittsburgh School’s normative functionalism has germinated from the seed of Sellars’ ‘psychological nominalism’ and cannot be separated from it. Second, no philosophical question or approach can be free of competing claims as to the manner in which human beings think, communicate, act, and know. As a result, normative functionalism (insofar as it is a natural extension of psychological nominalism) is relevant to many philosophical disciplines, because it opposes nearly all the traditional views concerning how the human intellect comes into being and functionally operates. (shrink)

Alvin Plantinga has proposed a fascinating epistemology, one which he considers to be completely naturalized. Critical to his epistemology is the notion of a 'design plan' which circumscribes the function of organs or systems. Ernest Sosa has objected to Plantinga by using Donald Davidson's Swampman thought experiment, according to which a bolt of lightning randomly assembles a physical duplicate of a person, including one's neurological structure. The Swampman would have no design plan and as such would constitute a counterexample to (...) Plantinga's epistemology. Plantinga responded to Sosa that the Swampman may not be metaphysically possible so he is not disturbed by it conflicting with his epistemology and, at any rate, we would still ascribe functions (and thus design plants) the Swampman's organs and systems. In this essay I will argue that 1) a stronger case can be made demonstrating that the Swampman is not metaphysically possible and 2) at any rate the Swampman is not possible in an epistemological sense; that is, it could not know anything. (shrink)

Nonreductive physicalists have a causal exclusion problem. Given certain theses all physicalists accept, including psychophysical supervenience and the causal closure of the physical realm, it is difficult to see how irreducible mental phenomena could make a causal difference to the world. The upshot, according to those who push the problem, is that we must embrace reductive physicalism. Only then is mental causation saved. -/- Grant the argument, at least provisionally. Here our focus is the conditional question: What form should one's (...) reductionism take if it is motivated in part by the exclusion problem? Must one be a type identity theorist, or are alternative reductive views available, as Jaegwon Kim has suggested more than once? (shrink)

There are two constraints on any functionalist solution to the Mind-Body Problem construed as an answer to the question, “What is the relationship between the mental properties and relations (hereafter, simply the mental properties) and physical properties and relations?” The first constraint is that it must actually address the Mind-Body Problem and not simply redefine the debate in terms of other, more tractable, properties (e.g., the species-specific property of having human-pain). Such moves can be seen to be spurious by the (...) very multiple-realizability intuitions that motivate functionalism in the first place. For, according to those intuitions, it is possible for a being to experience pain, have beliefs, etcetera, and yet not only to be of a different species, but to have an entirely different material constitution from human beings. (shrink)

Realization can be roughly understood as a kind of role-playing, a relationship between a property that plays a role and a property characterized by that role. This rough sketch previously received only moderate elaboration; recently, however, several substantive theories of realization have been proposed. But are there any general constraints on a theory of realization? What is a theory of realization supposed to accomplish? I first argue that a view of realization is viable, in part, to the extent that physical (...) realization under that view explains or accounts for why instances of realized properties are necessitated by how things are physically in a modally strong sense. In this sense, I claim that physical realization should explain physical supervenience. I then call into question two alternative desiderata and raise a challenge for attempts to explicate realization in terms of isomorphism or analogy. Finally, I explain how a causal-functional account of realization, as well as less demanding accounts, can meet the preferred desideratum. (shrink)

Functionalists about truth employ Ramsification to produce an implicit definition of the theoretical term _true_, but doing so requires determining that the theory introducing that term is itself true. A variety of putative dissolutions to this problem of epistemic circularity are shown to be unsatisfactory. One solution is offered on functionalists' behalf, though it has the upshot that they must tread on their anti-pluralist commitments.

“Triviality arguments” against functionalism in the philosophy of mind hold that the claim that some complex physical system exhibits a given functional organization is either trivial or has much less content than is usually supposed. I survey several earlier arguments of this kind, and present a new one that overcomes some limitations in the earlier arguments. Resisting triviality arguments is possible, but requires functionalists to revise popular views about the “autonomy” of functional description.

Explanations of how psychological capacities are carried out often invoke functional brain areas. I argue that such explanations cannot succeed. Psychological capacities are carried out by identifiable entities and their activities in the brain, but functional brain areas are not the relevant entities. I proceed by assuming that if functional brain areas did carry out psychological capacities, then these brain areas could be included in descriptions of mechanisms. And if functional brain areas participate in mechanisms, then they must engage in (...) activities. A number of ways in which we might understand the claim that functional brain areas engage in activities are examined. None are successful, and so one conclusion is that functional brain areas do not participate in mechanisms. Consequently, they are not the entities that carry out psychological capacities. (shrink)

In his recent article ‘Consciousness and Reduction’, Ausonio Marras argues that functional reduction must appeal to bridge laws and thus does not represent a genuine alternative to Nagelian reduction. In response, I first argue that even if functional reduction must use bridge laws, it still represents a genuine alternative to Nagelian reduction. Further, I argue that Marras does not succeed in showing that functional reduction must use bridge laws. Introduction Nagelian Reduction, Functional Reduction, and Bridge Laws Marras on Functional Reduction (...) The Logical Space of ‘Bridge Law’ Views of Reduction [RP] as an Account of Realization Conclusion CiteULike Connotea Del.icio.us What's this? (shrink)

The main message of the paper is that there is a disconnect between what many philosophers of mind think of as the scientific practice of reductive or reductionist explanation, and what the most relevant scientific work is actually like. I will sketch what I see as a better view, drawing on various ideas in recent philosophy of science. I then import these ideas into the philosophy of mind, to see what difference they make.1 At the end of the paper I (...) address a possible objection: the familiar package of ideas I reject in the philosophy of science should not be lightly discarded, because other popular views on fundamental issues depend on positions that I want to reject. I reply that those apparently attractive further ideas are not worth holding onto. (shrink)

Concerns about ‘mental causation’ are concerns about how it is possible for mental states to cause anything to happen. How does what we believe, want, see, feel, hope, or dread manage to cause us to act? Certain positions on the mind-body problem—including some forms of physicalism—make such causation look highly problematic. This entry sketches several of the main reasons to worry, and raises some questions for further investigation.

The paper sets out a new strategy for theory reduction by means of functional sub-types. This strategy is intended to get around the multiple realization objection. We use Kim's argument for token identity (ontological reductionism) based on the causal exclusion problem as starting point. We then extend ontological reductionism to epistemological reductionism (theory reduction). We show how one can distinguish within any functional type between functional sub-types. Each of these sub-types is coextensive with one type of realizer. By this means, (...) a conservative theory reduction is in principle possible, despite multiple realization. We link this account with Nagelian reduction, as well as with Kim's functional reduction. (shrink)

Contemporary Debates in Philosophy of Mind showcases the leading contributors to the field, debating the major questions in philosophy of mind today. Comprises 20 newly commissioned essays on hotly debated issues in the philosophy of mind Written by a cast of leading experts in their fields, essays take opposing views on 10 central contemporary debates A thorough introduction provides a comprehensive background to the issues explored Organized into three sections which explore the ontology of the mental, nature of the mental (...) content, and the nature of consciousness. (shrink)

Role-functionalism for mental events attempts to avoid epiphenomenalism without psychophysical identities. The paper addresses the question of whether it can succeed. It is argued that there is considerable reason to believe it cannot avoid epiphenomenalism, and that if it cannot, then it is untenable. It is pointed out, however, that even if role- functionalism is indeed an untenable theory of mental events, a role-functionalism account of mental dispositions has some intuitive plausibility.