Dual-process and dual-system theories in both cognitive and social psychology have been subjected to a number of recently published criticisms. However, they have been attacked as a category, incorrectly assuming there is a generic version that applies to all. We identify and respond to 5 main lines of argument made by such critics. We agree that some of these arguments have force against some of the theories in the literature but believe them to be overstated. We argue (...) that the dual-processing distinction is supported by much recent evidence in cognitive science. Our preferred theoretical approach is one in which rapid autonomous processes are assumed to yield default responses unless intervened on by distinctive higher order reasoning processes. What defines the difference is that Type 2 processing supports hypothetical thinking and load heavily on working memory. (shrink)

Despite their popularity, dual process accounts of human reasoning and decision-making have come under intense scrutiny in recent years. Cognitive scientists and philosophers alike have come to question the theoretical foundations of the ‘standard view’ of dual process theory and have challenged the validity and relevance of evidence in support of it. Moreover, attempts to modify and refine dual process theory in light of these challenges have generated additional concerns about its applicability (...) and refutability as a scientific theory. With these concerns in mind, this paper provides a critical review of dual process theory in economics, focusing on its role as a psychological framework for decision modeling in behavioral economics and neuroeconomics. I argue that the influx of criticisms against dual process theory challenge the descriptive accuracy of dualistic decision models in economics. In fact, the case can be made that the popularity of dual process theory in economics has less to do with the empirical success of dualistic decision models, and more to do with the convenience that the dual process narrative provides economists looking to explain-away decision anomalies. This leaves behavioral economists and neuroeconomists with something of a dilemma: either they stick to their purported ambitions to give a realistic description of human decision-making and give up the narrative, or they revise and restate their scientific ambitions. (shrink)

A step towards a theory of consciousness would be to characterise the effect of consciousness on information processing. One set of results suggests that the effect of consciousness is to interfere with computations that are optimally performed non-consciously. Another set of results suggests that conscious, system 2 processing is the home of norm-compliant computation. This is contrasted with system 1 processing, thought to be typically unconscious, which operates with useful but error-prone heuristics. -/- These results can be reconciled by (...) separating out two different distinctions: between conscious and non-conscious representations, on the one hand, and between automatic and deliberate processes, on the other. This pair of distinctions is used to illuminate some existing experimental results and to resolve the puzzle about whether consciousness helps or hinders accurate information processing. This way of resolving the puzzle shows the importance of another category, which we label ‘type 0 cognition’, characterised by automatic computational processes operating on non-conscious representations. (shrink)

This anthology offers a unique collection of contributions focusing on the discussion about the so-called dual-process theories within the field of moral psychology. In general, dual-process theories state that in cognitive systems, two sorts of processes can be differentiated: an affective, associative process and an analytical, rule-based process. This distinction recently entered the debate on the relationship between intuitive and rational approaches to explaining the phenomenon of moral judgment. The increasing interest in these theories (...) raises questions concerning their general impact on social contexts. The anthology aims at presenting stepping-stones of an analysis of the merits and drawbacks of this development. For that purpose, the authors discuss general questions concerning the relationship between ethics and empirical sciences, methodological questions, reassessments of established terminology and societal implications of dual-process theories in moral psychology. (shrink)

Dual process theory proposes clusters of features that form two dichotomous groups in cognition. One standing internal issue is defining what the reference of these two dichotomous groups could be in the mind or brain. Does dual process theory speak of two systems, types, minds, modes, kinds or just metaphors? A particular common answer is that differences in clusters of features are evidence of different underlying systems, often called system 1 and system 2. However, (...) the suggestion to abandon the ‘system’ terminology is now common in the literature, but the consequences of doing so need to be addressed. This work reviews and critically discusses previous suggestions. (shrink)

The distinction between such differing approaches to cognition as connectionism and rule-based models is paralleled by a distinction between two basic modes of cognition postulated in the so-called dual-process theories. Integrating these theories with insights from hybrid systems might help solve the dilemma of combining the demands of evolutionary plausibility and computational universality. No single approach alone can achieve this.

This book presents a philosophical interpretation to numerical cognition based on dual process theories and heuristics. It shows how investigations in cognitive science can shed light on issues traditionally raised by philosophers of mathematics. The analysis will also help readers to better understand the relationship between current neuroscientific research and the philosophical reflection on mathematics. The author seeks to explain the acquisition of mathematical concepts. To accomplish this, he needs to answer two questions. How can the concepts of (...) approximate numerosity become an object of thought that is so accessible to our consciousness? How are these concepts refined and specified in such a way as to become numbers? Unfortunately, there is currently no model that can truly demonstrate the role of language in the development of numerical skills starting from approximate pre-verbal skills. However, the author details a solution to this problem: dual process theories. It is an approach widely used by theorists focusing on reasoning, decision making, social cognition, and consciousness. Here, he applies this approach to the studies on mathematical knowledge. He details the results brought about by psychological and neuroscientific studies conducted on numerical cognition by key neuroscientists. In the process, he develops the foundations of a new, potential philosophical explanation on mathematical knowledge. (shrink)

Dual Process Theory is currently a popular theory for explaining why we show bounded rationality in reasoning and decision-making tasks. This theory proposes there must be a sharp distinction in thinking to explain two clusters of correlational features. One cluster describes a fast and intuitive process, while the other describes a slow and reflective one. A problem for this theory is identifying a common principle that binds these features together, explaining why they form (...) a unity, the unity problem. To solve it, a hypothesis is developed combining embodied predictive processing with symbolic classical approaches. The hypothesis, simplified, states that Type 1 processes are bound together because they rely on embodied predictive processing whereas Type 2 processes form a unity because they are accomplished by symbolic classical cognition. To show that this is likely the case, the features of Dual Process Theory are discussed in relation to these frameworks. (shrink)

This commentary is sympathetic to De Neys's revision of dual-process theory but argues for a modification to his position on exclusivity and proposes a bold further revision, envisaging a dual-process theory 3.0, in which system 1 not only initiates system 2 thinking but generates and sustains it as well.

Two prevailing accounts of the structure of the mind have been provided, respectively, by the Dual System Theory and by the Massive Modularity Hypothesis. It has been claimed, however, that they cannot both be true at the same time, i.e., that they are incompatible and, thus, that one of them must be abandoned. I will offer some arguments to challenge this claim. I will show that a plausible understanding of each theory makes it possible for them both (...) to be true at the same time. Moreover, I will argue that by appealing to each other they can offer a more complete and detailed account of the architecture of the mind. (shrink)

The biggest benefit of dual-process theory lies in its role as a benchmark theory that, regardless of its empirical plausibility, serves as a starting point for better and more domain-specific models. In this sense, dual-process theory is the Barbapapa of psychological theory – a blob-shaped creature that can be reshaped and adapted to fit in the context of any human behavior.

In this paper, I seek an account of the nature of epistemic intuition. Given the resources of Dual-Process Theory in Psychology, I argue that the intuitions of elite epistemologists, such as Fred Dretske, are not a priori, pre-theoretic, insights. Instead, they are a posteriori insights into the phenomena of knowledge, not the concept of knowledge. Dretske intuitions are technical, modal intuitions about hypothetical counterfactual cases using System II reflections. Such intuitions depended on thinking about the implications of (...) laws of nature in particular circumstances and were used to defend Dretske’s reliable indicator account of knowledge. That account suggested that one must have conclusive reasons when one has empirical knowledge that P. (shrink)

The direct social perception thesis claims that we can directly perceive some mental states of other people. The direct perception of mental states has been formulated phenomenologically and psychologically, and typically restricted to the mental state types of intentions and emotions. I will compare DSP to another account of mindreading: dual process accounts that posit a fast, automatic “Type 1” form of mindreading and a slow, effortful “Type 2” form. I will here analyze whether dual process (...) accounts’ Type 1 mindreading serves as a rival to DSP or whether some Type 1 mindreading can be perceptual. I will focus on Apperly and Butterfill’s dual process account of mindreading epistemic states such as perception, knowledge, and belief. This account posits a minimal form of Type 1 mindreading of belief-like states called registrations. I will argue that general dual process theories fit well with a modular view of perception that is considered a kind of Type 1 process. I will show that this modular view of perception challenges and has significant advantages over DSP’s phenomenological and psychological theses. Finally, I will argue that if such a modular view of perception is accepted, there is significant reason for thinking Type 1 mindreading of belief-like states is perceptual in nature. This would mean extending the scope of DSP to at least one type of epistemic state. (shrink)

How many minds do you have? If you are a normal human, I think only one, but a number of dual-process theorists have disagreed. As an explanation of human irrationality, they divide human reasoning into two: Type-1 is fast, associative, and automatic, while Type-2 is slow, rule-based, and effortful. Some go further in arguing that these reasoning processes constitute (or are partly constitutive of) two minds. In this paper, I use the Star Trek ‘Trill’ species to illuminate the (...) condition for the existence of “two minds in one brain” (Evans 2010, 3). After carefully outlining the two dominate versions of dual-process theory (default-interventionism, espoused by Evans, Stanovich, and Kahneman, and parallel-competitive theory, espoused by Sloman, Frankish, and Carruthers) and contrasting each with a one-system alternative, I argue that these three views should be understood as existing on a continuum: there are some theories that could plausibly be characterized as either one-system or default-interventionist, and the distinction between default-interventionism and parallelcompetitive theory is not as clean-cut as usually assumed. I then argue, using the conceptual claims I defended using the science fiction cases, that default-interventionist dual-process theory is not compatible with the claim that humans have two minds (contra Evans and Stanovich). (shrink)

From experience, we know that some cognitive processes are effortless and automatic (or nearly automatic), while others are hard and deliberate. Dual process (DP) accounts of human cognition explain these differences by positing two qualitatively distinct types of cognitive processes within the human mind—types that cannot be reduced to each other. Because DP constructs are bound to show up in discourse on human cognition, decision-making, morality, and character formation, moral philosophers should take DP accounts seriously. Here, I provide (...) an overview of the current state of DP accounts—their basic tenets, major concepts, and the various models of the DP framework—and note some of its more salient criticisms from the psychological research community. Finally, I show that DP accounts’ commitment to a real qualitative distinction between rational and non-rational human behavior puts them at odds with a Thomistic/Aristotelian view of practical rationality. (shrink)

Volume 26, Issue 2, May 2020, Page 151-158.

De Neys (2021) argues that the debate between single- and dual-process theorists of thought has become both empirically intractable and scientifically inconsequential. I argue that this is true only under the traditional framing of the debate—when single- and dual-process theories are understood as claims about whether thought processes share the same defining properties (e.g., making mathematical judgments) or have two different defining properties (e.g., making mathematical judgments autonomously versus via access to a central working memory capacity), (...) respectively. But if single- and dual-process theories are understood in cognitive modeling terms as claims about whether thought processes function to implement one or two broad types of algorithms, respectively, then the debate becomes scientifically consequential and, presumably, empirically tractable. So, I argue, the correct response to the current state of the debate is not to abandon it, as De Neys suggests, but to reframe it as a debate about cognitive models. (shrink)

Recent work in cognitive modelling has found that most of the data that has been cited as evidence for the dual-process theory (DPT) of reasoning is best explained by non-linear, “monotonic” one-process models (Stephens et al., 2018, 2019). In this paper, I consider an important caveat of this research: it uses models that are committed to unrealistic assumptions about how effectively task conditions can isolate Type-1 and Type-2 reasoning. To avoid this caveat, I develop a coordinated (...) theoretical, experimental, and modelling strategy to better test DPT. First, I propose that Type-1 and Type-2 reasoning are defined as reasoning that precedes and follows metacognitive control, respectively. Second, I argue that reasoning that precedes and follows metacognitive control can be effectively isolated using debiasing paradigms that manipulate metacognitive heuristics (e.g., processing fluency) to prevent or trigger metacognitive control, respectively. Third, I argue that monotonic modelling can allow us to decisively test DPT only when we use them to analyse data from this particular kind of debiasing paradigm. (shrink)

Implicit cognition is cognition that happens automatically and (typically) non-consciously. In moral psychology, implicit cognition is almost always understood in terms of dual process models of moral judgment. In this chapter, we address the question whether implicit moral judgment is usefully cashed out in terms of automatic (“type 1”) processes, and what the limitations of this approach are. Our chapter has six sections. In (1), we provide a brief overview of dual process models of domain-general (moral (...) and non-moral) cognition. (2) reviews a recent debate regarding the soundness of dual process models to begin with. Section (3) is about dual process accounts of moral judgment specifically. The last three sections then survey attempts to go beyond a simplistic automatic/controlled (“type 2”) distinction in conceptualizing implicit moral cognition. Recently, three main theoretical approaches have emerged, which all revolve around the questions whether type 2 processing can successfully penetrate implicit moral cognition. First, rational learning approaches highlight how episodes of moral learning can feed back into and shape our moral intuitions (4). Second, so-called triple process models suggest that automatic cognitive outputs can under certain circumstances be reined in by reflective cognition (5). Finally, recent evidence shows that moral reasoning is not as impotent as earlier developments in empirical moral psychology claimed to demonstrate (6). (shrink)

In response to the claim that the properties typically used to distinguish System 1 from System 2 crosscut one another, Carruthers, Evans, and Stanovich have abandoned the System 1/System 2 distinction. Evans and Stanovich both opt for a dual-process theory, according to which Type-1 processes are autonomous and Type-2 processes use working memory and involve cognitive decoupling. Carruthers maintains a two-system account, according to which there is an intuitive system and a reflective system. I argue that these (...) defenses of dual-process theory face two problems. First, as pointed out by Sloman, these new dual-process theories cast the net of “reasoning” too wide. Second, and more importantly, this singular distinction cannot accomplish the explanatory work needed to support dual-process theory. These theorists must fall back on using various properties from the Standard Menu in explanations, thereby committing these accounts to a “Standard View” that they had hoped to avoid. Thus, these theorists face a.. (shrink)

In this commentary on Stanovich & West (S&W) we call attention to two points: (1) Freud's original dual process theory, which antedates others by some seventy-five years, deserves inclusion in any consideration of dual process theories. His concepts of primary and secondary processes (Systems 1 and 2, respectively) anticipate significant aspects of current dual process theories and provide an explanation for many of their characteristics. (2) System 1 is neither rational nor irrational, but (...) instead a-rational. Nevertheless, both the a-rational System 1 and the rational System 2 can each have different roles in enhancing evolutionary fitness. Lastly, System 1 operations are incorrectly deemed “rational” whenever they increase evolutionary fitness. (shrink)

Dual-process theories hold that there are two distinct processing modes available for many cognitive tasks: one that is fast, automatic and non-conscious, and another that is slow, controlled and conscious. Typically, cognitive biases are attributed to type 1 processes, which are held to be heuristic or associative, and logical responses to type 2 processes, which are characterised as rule-based or analytical. Dual-system theories go further and assign these two types of process to two separate reasoning systems, (...) System 1 and System 2 – a view sometimes described as ‘the two minds hypothesis’. It is often claimed that System 2 is uniquely human and the source of our capacity for abstract and hypothetical thinking. This study is an introduction to dual-process and dual-system theories. It looks at some precursors, surveys key work in the fields of learning, reasoning, social cognition and decision making, and identifies some recent trends and philosophical applications. (shrink)

This excellent target article helps to resolve a problem for dual-process theories of higher cognition. Theorists posit two systems, one of which appears to be conscious and volitional. It seems to control some behaviours but to confabulate explanations for others. I argue that this system is only conscious in an illusory sense and that all self-explanations are confabulatory, as Carruthers suggests.

I present a critical discussion of dual-process theories of reasoning and decision making with particular attention to the nature and role of Type 2 processes. The original theory proposed...

Joshua Greene and his colleagues have proposed a dual-process theory of moral decision-making to account for the effects of emotional responses on our judgments about moral dilemmas that ask us to contemplate causing direct personal harm. Early formulations of the theory contrast emotional and cognitive decision-making, saying that each is the product of a separable neural system. Later formulations emphasize that emotions are also involved in cognitive processing. I argue that, given the acknowledgement that emotions inform (...) cognitive decision-making, a single-process theory can explain all of the data that have been cited as evidence for Greene’s theory. The emotional response to the thought of causing harm may differ in degree, but not in kind, from other emotions influencing moral decision-making. (shrink)

According to the dual-process account of moral judgment, deontological and utilitarian judgments stem from two different cognitive systems. Deontological judgments are effortless, intuitive and emotion-driven, whereas utilitarian judgments are effortful, reasoned and dispassionate. The most notable evidence for dual-process theory comes from neuroimaging studies by Joshua Greene and colleagues. Greene has suggested that these empirical findings undermine deontology and support utilitarianism. It has been pointed out, however, that the most promising interpretation of his argument does (...) not make use of the empirical findings. In this paper, I engage with recent attempts by Greene to vindicate the moral significance of dual-process theory and the supporting neuroscientific findings. I consider their potential moral significance with regard to three aspects of Greene’s case against deontology: the argument from morally irrelevant factors, the functionalist argument and the argument from confabulation. I conclude that Greene fails to demonstrate how neuroscience and dual-process theory in general can advance moral theorizing. (shrink)

Dual-process models of cognition suggest that there are two types of thought: autonomous Type 1 processes and working memory dependent Type 2 processes that support hypothetical thinking. Models of creative thinking also distinguish between two sets of thinking processes: those involved in the generation of ideas and those involved with their refinement, evaluation, and/or selection. Here we review dual-process models in both these literatures and delineate the similarities and differences. Both generative creative processing and evaluative creative (...) processing involve elements that have been attributed to each of the dual processes of cognition. We explore the notion that creative thinking may rest upon the nature of a shifting process between Type 1 and Type 2 dual processes. We suggest that a synthesis of the evidence bases on dual-process models of cognition and of creative thinking, together with developing time-based approaches to explore the shifting process, could better inform the development of i.. (shrink)

In this paper, I show that the question of how dual process theories of reasoning and judgement account for conflict between System 1 (heuristic) and System 2 (analytic) processes needs to be explicated and addressed in future research work. I demonstrate that a simple additive probability model that describes such conflict can be mapped on to three different cognitive models. The pre-emptive conflict resolution model assumes that a decision is made at the outset as to whether a heuristic (...) or analytic process will control the response. The parallel-competitive model assumes that each system operates in parallel to deliver a putative response, resulting sometimes in conflict that then needs to be resolved. Finally, the default-interventionist model involves the cueing of default responses by the heuristic system that may or may not be altered by subsequent intervention of the analytic system. A second, independent issue also emerges from this discussion. The superior performance of higher-ability participants on reasoning tasks may be due to the fact that they engage in more analytic reasoning ( quantity hypothesis ) or alternatively to the fact that the analytic reasoning they apply is more effective ( quality hypothesis ). (shrink)

This is an excerpt from the contentThere has been increasing interest in recent years in dual process theories of human thought. This special issue of Mind and Society reflects this interest, some criticisms of these theories, and the major topics that have been discussed and debated as a result. There is the basic topic of how the postulated dual processes should be defined in the first place. Do these processes have essential defining features that can be distinguished (...) from less central correlates? Can decoupling, metarepresentation, or working memory be used for making the essential distinction?There are questions about how these dual processes work and interact. What do dual process theories tell us about different modes of thought and insight in problem solving? One topic that could throw light on these questions is creative thinking. It deals with novelties and yet can be rule following. It can be an aspect of hypothetical thinking, but how far it is a conscious or unconscious process is still unknown. There is th. (shrink)

The hypothesis that human reasoning and decision-making can be roughly modeled by Expected Utility Theory has been at the core of decision science. Accumulating evidence has led researchers to modify the hypothesis. One of the latest additions to the field is Dual Process theory, which attempts to explain variance between participants and tasks when it comes to deviations from Expected Utility Theory. It is argued that Dual Process theories at this point cannot replace (...) previous theories, since they, among other things, lack a firm conceptual framework, and have no means of producing independent evidence for their case. (shrink)

This dissertation is devoted to dual-process theories, widely discussed in the recent literature in cognitive science. The author argues for a significantly modified version of the account suggested by Samuels (2009), replacing the distinction between ‘Systems’ with a distinction between ‘Types of processes,’ which allows a critique of both the (only) modularist accounts and the accounts describing a deep difference between two systems each having their specificities (functional, phenomenological and neurological). In the account of dual-process theories (...) developed here, the distinction between ‘Types of processes’ is considered, a priori, only as a heuristic distinction allowing to better understand the mind and to explain some of its properties. The main idea defended in this dissertation is that cognitive processes should be distinguished by their position in a multidimensional conceptual space allowing researchers to consider all of the characteristics and peculiarities attributed to a process, which is preferable to accounts forcing the process into either ‘System’ or either ‘Type’ identified in the most influential approaches (cf. Evans, 2008). Once this research program is in place, it will become possible to revise the concepts used and the categories defined to ground anew some of the notions we find in the literature (‘module,’ ‘System 1 / 2,’ etc.). The argument is made in three steps: -/- 1) The first chapter aims at a clarification of the notion of ‘module’ commonly used in cognitive science. Against the accounts aiming at a weakening of the notion in order to classify all of the mind’s processes as modular, the author – following most notably Faucher and Poirier (2009) and Samuels (2006) – casts doubt on how this notion is used by many influential authors, particularly in evolutionary psychology (e.g. Barrett, Carruthers, Cosmides, Tooby). -/- 2) The objective of the second chapter is to present, examine and criticize many dual-process theories and to suggest that no theory currently discussed is adequate to describe the architecture of mind. The accounts, especially influent or representative, suggested by Stanovich (1999; 2004; 2009), by Evans (2008; 2009), by Lieberman (2007; 2009) and by Carruthers (2006; 2009), are examined. -/- 3) In the third chapter, the author criticizes the framework developed by Samuels (2009) before developing his own account of dual-process theories and discussing some of its advantages. (shrink)

In this study, we examine the belief bias effect in syllogistic reasoning under both standard presentation and in a condition where participants are required to respond within 10 seconds. As predicted, the requirement for rapid responding increased the amount of belief bias observed on the task and reduced the number of logically correct decisions, both effects being substantial and statistically significant. These findings were predicted by the dual-process account of reasoning, which posits that fast heuristic processes, responsible for (...) belief bias, compete with slower analytic processes that can lead to correct logical decisions. Requiring rapid responding thus differentially inhibits the operation of analytic reasoning processes, leading to the results observed. (shrink)

ABSTRACTIn order to explain the effects found in the heuristics and biases literature, dual-process theories of reasoning claim that human reasoning is of two kinds: Type-1 processing is fast, automatic, and associative, while Type-2 reasoning is slow, controlled, and rule based. If human reasoning is so divided, it would have important consequences for morality, epistemology, and philosophy of mind. Although dual-process theorists have typically argued for their position by way of an inference to the best explanation, (...) they have generally failed to consider alternative hypotheses. Worse still, it is unclear how we might test dual-process theories. In this article, I offer a one-system theory, which I call the Sound-Board Account of Reasoning, according to which there is one reasoning system which is flexible, allowing the properties used to distinguished Type-1 and Type-2 reasoning to cross-cut one another. I empirically distinguish my theory from the two dominant versions of dual-process theory (parallel... (shrink)

According to the standard view in philosophy, intentionality is the mark of genuine action. In psychology, human cognition and agency are now widely explained in terms of the workings of two distinct systems (or types of processes), and intentionality is not a central notion in this dual-system theory. Further, it is often claimed, in psychology, that most human actions are automatic, rather than consciously controlled. This raises pressing questions. Does the dual-system theory preserve the philosophical account (...) of intentional action? How much of our behavior is intentional according to this view? And what is the role of consciousness? I will propose here a revised account of intentional action within the dual-system framework, and we will see that most of our behavior can qualify as intentional, even if most of it is automatic. An important lesson will be that philosophical accounts of intentional action need to pay more attention to the role of consciousness in action. (shrink)

Dual-Process Theories (D-PTs) claim there are two qualitatively different types of processes in the human brain-mind. Despite forming the basis for several areas of cognitive science, they are still shrouded in ambiguity: critics erroneously attack D-PTs as a whole (e.g., Evans and Stanovich Perspectives on Psychological Science, 8(3), 2013), the qualitative/quantitative distinction is not clear enough (De Neys Perspectives on Psychological Science 16 (6): 1412–1427, 2021; Dewey 2022) and, given this criterion, deciding between qualitative or quantitative differences may (...) even be scientifically irrelevant (De Neys 2021). As a way of disambiguating the discussion and clarifying what exactly means to claim the existence of a second type of process, I define two possible categories of D-PT: The substantial and the instrumental. In the substantial case, Type 2 processes are subpersonal level ones. In the instrumental case, Type 2 processing is a personal level phenomenon that does not necessarily imply subpersonal level Type 2 processes. Discussing the different implications of each of the categories, I use as a main example to illustrate the ambiguity – and the exercise of disambiguation – the model proposed by Evans and Stanovich (2013), making clear its substantial character, and contrast it with Frankish’ (2009) – a clear case of instrumental D-PT. Finally, I discuss the contributions this distinction can make. By making the discussion clearer, it can provide a relatively unanimous framework for dual- and single-process theorists (the instrumental version) and clearer desiderata for those wishing to defend the substantive one. (shrink)