Stanley Bernard Klein

NOTE: This version is substantially modified from the original MS, downloaded on 5/29/2026. It is the version submitted for publication.//// Most contemporary neuropsychiatric accounts of Capgras delusions rely on two-factor cognitive models. These theories posit that the delusion is an ad hoc, multi-variable hypothesis invented to explain a qualitative deficit, such as a loss of affective "glow", sense of familiarity or a violation of expectation. Recently, Bayesian predictive processing frameworks have attempted to simulate this deficit by postulating complex, mathematical calculations and manipulated precision ratios. This paper takes issue with both frameworks in favor of a more parsimonious, one-factor experiential account. We argue that the loss of familiarity or violation of expectation is not the cause of Capgras. Rather, it is the downstream result of a disruption of sensed ownership over one's perceptual states, resulting from failure to take personal ownership of one's mental content. Instead of a Bayesian calculation, the brain experiences a localized structural breakdown in the hardware that “tags” mental content as "mine". Content is successfully retrieved, but cannot be bound to the self due to failure of this normally affixed ownership signature. By modeling "mineness" not as a single, global light switch, but as a localized tag embedded within distinct, modular cognitive subsystems, we resolve the historical "specificity problem" plaguing one-factor theories without reverting to ad hoc multi-factor mechanisms. The Capgras delusion is presented as the direct, rational narrative consequence of navigating an un-owned perceptual state.

Episodic memory is a major area of research in psychology. Initially viewed as a distinct store of information derived from experienced episodes, episodic memory is understood today as a form of mental "time travel" into the personal past. Recent research has revealed striking similarities between episodic memory - past-oriented mental time travel - and future-oriented mental time travel (FMTT). Seeing the Future: Theoretical Perspectives on Future-Oriented Mental Time Travel brings together leading contributors in both empirical and theoretical disciplines to present the first interdisciplinary look at the human to imagine future scenarios. Chapters focus on the challenging conceptual and theoretical questions raised by FMTT, covering themes such as: varieties of future-oriented cognition; relationships between FMTT and episodic memory; subjective temporality in FMTT; the self in FMTT; and functional, evolutionary and comparative, developmental, and clinical perspectives on FMTT. With its focus on the conceptual issues at the heart of fast-developing research on FMTT, this edited volume will serve graduate students to senior scholars working on or interested in FMTT and related areas as a synthesis of current theoretical thinking and a source of questions for future FMTT research.

In this paper I discuss philosophical and psychological treatments of the question “how do we decide that an occurrent mental state is a memory and not, say a thought or imagination?” This issue has proven notoriously difficult to resolve, with most proposed indices, criteria and heuristics failing to achieve consensus. Part of the difficulty, I argue, is that the indices and analytic solutions thus far offered seldom have been situated within a well-specified theory of memory function. As I hope to show, when such an approach is adopted, not only does a new, functionally-grounded answer emerge; we also gain insight into the adaptive significance of the process proposed to underwrite our belief in the memorial status of a mental state (i.e., autonoetic awareness).

In a recent set of articles (Klein et al., 2023; Klein & Loftus, 2024), my colleagues and I used the logic of adaptationism—the application of evolutionary principles to study the functional design of naturally selected systems (e.g., Klein et al., 2002)—to help make sense of the role natural selection played in the evolution of consciousness. To avoid well-known, seemingly intractable problems that accompany efforts to explain “how consciousness is possible in a world that consists in physical objects and their relations” (the so-called “hard problem of consciousness”), we limited investigation to the question of “why natural selection favored consciousness?” In the present article, I try to make amends for this evasion by addressing some of the conceptual challenges posed by the hard problem. Drawing on insights from Klein et al.’s (2023) evolutionary excursion into the why of consciousness, I identify a potential alteration in the referential identity of “subject” and “object” when they are taken as properties of a mental state, and discuss how these changes might offer insight into the how question of consciousness.  

Klein, Nguyen, & Zhang (in press) argued that the evolutionary transition from respondent to agent during the Cambrian Explosion would be a promising vantage point from which to gain insight into the evolution of organic sentience. They focused on how increased competition for resources -- in consequence of the proliferation of new, neurally sophisticated life-forms -- made awareness of the external world (in the service of agentic acts) an adaptive priority. The explanatory scope of Klein et al (in press) was limited to consideration of the conscious apprehension of externally sourced content – i.e., content delivered from the sensory registration of objects occupying phenomenal space. But consciousness – at least for humans -- takes its objects from internal as well as external sources. In the present article we extend their analysis to the question of how internally sourced content (i.e., mental states) became the object of conscious apprehension.

Laplacean Determinism (his so-called demon argument) is the thesis that every event that transpires in a closed universe is a physical event caused (i.e., determined) in full by some earlier event in accord with laws that govern their behavior. On this view, it is possible, in principle, to make perfect predictions of the state of the universe at any time Tn on the basis of complete knowledge of the state of the universe at time T1. Thus, if identity theory, epiphenomenalism or any other instantiation of Laplacean Determinism is correct, mental events such as free will, intention and other forms of mental agency are tricks of the mind, misleading us into believing our volitional concerns have traction in a world ruled entirely by physical circumstance. Not surprisingly, advocates of free will and related acts of human volition have engaged in spirited debate with adherents to Laplacean orthodoxy, the results of which have been far from conclusive. Rather than join these deliberations, I wholly embrace the demon argument and then ask “what are the consequences of this allegiance?” As I hope to show, acceptance of this argument commits one to a belief in the existence of human precognition. This, I suggest, is a consequence that does not fit comfortably within a contemporary scientific worldview.

In this paper we argue that autobiographical memory can be conceptualized as a mental state resulting from the interplay of a set of psychological capacities?self-reflection, self-agency, self-ownership and personal temporality?that transform a memorial representation into an autobiographical personal experience. We first review evidence from a variety of clinical domains?for example, amnesia, autism, frontal lobe pathology, schizophrenia?showing that breakdowns in any of the proposed components can produce impairments in autobiographical recollection, and conclude that the self-reflection, agency, ownership, and personal temporality are individually necessary and jointly sufficient for autobiographical memorial experience. We then suggest a taxonomy of amnesic disorders derived from consideration of the consequences of breakdown in each of the individual component processes that contribute to the experience of autobiographical recollection

The explanatory challenge of sentience is known as the “hard problem of consciousness”: How does subjective experience arise from physical objects and their relations? Despite some optimistic claims, the perennial struggle with this question shows little evidence of imminent resolution. In this article I focus on the “why” rather than on the “how” of sentience. Specifically, why did sentience evolve in organic lifeforms? From an evolutionary perspective this question can be framed: “What adaptive problem(s) did organisms face in their evolutionary past and how were those challenges met? I argue that sentience was a critical component of the adaptive solution (i.e., adopting an agentic stance) to increasingly complex and unpredictable demands placed on vertebrates approximately 500 million years ago (the so-called Cambrian explosion). One consequence of taking an agentic stance is that it freed the organism from its neural moorings, positioning it within phenomenal space outside its brain.

I argue that academic psychology’s quest to achieve scientific respectability by reliance on quantification and objectification is deeply flawed. Specifically, psychological theory typically cannot support prognostication beyond the binary opposition of “effect present/effect absent”. Accordingly, the “numbers” assigned to experimental results amount to little more than affixing names (e.g., more than, less than) to the members of an ordered sequence of outcomes. This, in conjunction with the conceptual under-specification characterizing the targets of experimental inquiry, is, I contend, a primary reason why psychologists find it difficult to discriminate between competing, explanations of the effects of mind on behavior. Absent well-specified theory capable of enabling precise and detailed quantitative prediction, inferring underlying mental mechanisms from experimental outcomes becomes a difficult, if not impossible, task.

Drawing on ideas from philosophy (in particular, epistemology), I argue that one of memory’s most important functions is to provide its owner with knowledge of the physical world. This knowledge helps satisfy the organism’s need to confer stability on an ever-changing reality so the objects in which it consists can be identified and reidentified. I then draw a distinction between sources of knowledge (i.e., from physical vs. subjective reality) and argue—based on evolutionary principles—that because memory was designed by natural selection to interface with the physical world, knowledge acquired via sensory/perceptual experiences should be better remembered than internally generated knowledge made available by introspection. A study conducted to test this hypothesis provides support. I conclude that a serious interdisciplinary approach to issues typically considered the purview of psychology best enables researchers to craft well-specified, theoretically based hypotheses that directly target functions of the mind.

Although the dream narrative, of (bio)logical necessity, originates with the dreamer, s/he typically does not know this. For the dreamer, the dream world is the real world. In this article I argue that this nightly misattribution is best explained in terms of the concept of mental ownership (e.g., Albahari, 2006; Klein, 2015a; Lane, 2012). Specifically, the exogenous nature of the dream narrative is the result of an individual assuming perspectival, but not personal, ownership of content s/he authored (i.e., “The content in my head is not mine. Therefore it must be peripherally perceived”). Situating explanation within a theoretical space designed to address questions pertaining to the experienced origins of conscious content has a number of salutatory consequences. For example, it promotes predictive fecundity by bringing to light empirical generalizations whose presence otherwise might have gone unnoticed (e.g., the severely limited role of mental time travel within the dream narrative).

This Target paper is about the hard problem of phenomenal consciousness (i.e., how is subjective experience possible given the scientific presumption that everything from molecules to minerals to minds is wholly physical?). I first argue that one of the most valuable tools in the scientific arsenal (metaphor) cannot be recruited to address the hard problem due to the inability to forge connections between the stubborn fact of subjective experience and physically grounded models of scientific explanation. I then argue that adherence to the physicalist tenets of contemporary science has a limiting effect on a full appreciation of the phenomenon under discussion.

Memory of past episodes provides a sense of personal identity — the sense that I am the same person as someone in the past. We present a neurological case study of a patient who has accurate memories of scenes from his past, but for whom the memories lack the sense of mineness. On the basis of this case study, we propose that the sense of identity derives from two components, one delivering the content of the memory and the other generating the sense of mineness. We argue that this new model of the sense of identity has implications for debates about quasi-memory. In addition, articulating the components of the sense of identity promises to bear on the extent to which this sense of identity provides evidence of personal identity.

I argue that appreciation of the phenomenon of forgetting requires serious attention to its origins and place in nature. This, in turn, necessitates metaphysical inquiry as well as empirical backing – a combination likely to be eschewed by psychological orthodoxy. But, if we hope to avoid the conceptual vacuity that characterizes too much of contemporary psychological inquiry (e.g., Klein, 2012, 2014a, 2015a, 2016a), a “big picture” approach to phenomena of interest is essential. Adopting this investigative posture turns the “received view” of the relation between remembering and forgetting on its head: Rather than treated as the result of breakdowns and limitations of biologically engineered systems of remembering, forgetting is accorded elevated status as the driving force behind the evolution of organic systems of information retention.

This article builds on ideas presented in Klein (2015a) concerning the importance of a more nuanced, conceptually rigorous approach to the scientific understanding and use of the construct “memory”. I first summarize my model, taking care to situate discussion within the terminological practices of contemporary philosophy of mind. I then elucidate the implications of the model for a particular operation of mind – the manner in which content presented to consciousness realizes its particular phenomenological character (i.e., mode of presentation). Finally, I discuss how the model offers a reconceptualization of the technical language used by psychologists and neuroscientists to formulate and test ideas about memory.

In this paper I examine the concept of cross-temporal personal identity (diachronicity). This particular form of identity has vexed theorists for centuries -- e.g.,how can a person maintain a belief in the sameness of self over time in the face of continual psychological and physical change? I first discuss various forms of the sameness relation and the criteria that justify their application. I then examine philosophical and psychological treatments of personal diachronicity(for example,Locke's psychological connectedness theory; the role of episodic memory) and find each lacking on logical grounds, empirical grounds, or both. I conclude that to achieve a successful resolution of the issue of the self as a temporal continuant we need to draw a sharp distinction between the feeling of the sameness of one's self and the evidence marshaled in support of that feeling.

In this paper I argue for the importance of treating mental experience on its own terms. In defense of “experiential realism” I offer a critique of modern psychology’s all-too-frequent attempts to effect an objectification and quantification of personal subjectivity. The question is “What can we learn about experiential reality from indices that, in the service of scientific objectification, transform the qualitative properties of experience into quantitative indices?” I conclude that such treatment is neither necessary for realizing, nor sufficient for capturing, subjectively given states (such as perception, pain, imagery, fear, thought, memory) – that is, for understanding many of the principle objects of psychological inquiry. A “science of mind” that approaches its subject matter from a third-person perspective should, I contend, be treated with a healthy amount of informed skepticism.

In this paper I argue that much of the confusion and mystery surrounding the concept of "self" can be traced to a failure to appreciate the distinction between the self as a collection of diverse neural components that provide us with our beliefs, memories, desires, personality, emotions, etc (the epistemological self) and the self that is best conceived as subjective, unified awareness, a point of view in the first person (ontological self). While the former can, and indeed has, been extensively studied by researchers of various disciplines in the human sciences, the latter most often has been ignored -- treated more as a place holder attached to a particular predicate of interest (e.g., concept, reference, deception, esteem, image, regulation, etc). These two aspects of the self, I contend, are not reducible -- one being an object (the epistemological self) and the other a subject (the ontological self). Until we appreciate the difficulties of applying scientific methods and analysis to what cannot be reduced to an object of inquiry without stripping it of its essential aspect (its status as subject), progress on the "self", taken as a pluralistic construct, will continue to address only one part of the problems we face in understanding this most fundamental aspect of human experience.

In this paper I discuss philosophical and psychological treatments of the question "how do we decide that an occurrent mental state is a memory and not, say a thought or imagination?" This issue has proven notoriously difficult to resolve, with most proposed indices, criteria and heuristics failing to achieve consensus. Part of the difficulty, I argue, is that the indices and analytic solutions thus far offered seldom have been situated within a well-specified theory of memory function. As I hope to show, when such an approach is adopted, not only does a new, functionally-grounded answer emerge; we also gain insight into the adaptive significance of the process proposed to underwrite our belief in the memorial status of a mental state (i.e.,autonoetic awareness).

I examine some of the key scientific pre-commitments of modern psychology, and argue that their adoption has the unintended consequence of rendering a purely psychological analysis of mind indistinguishable from a purely biological treatment. And, since these pre-commitments sanction an “authority of the biological”, explanation of phenomena traditionally considered the purview of psychological analysis is fully subsumed under the biological. I next evaluate the epistemic warrant of these pre-commitments and suggest there are good reasons to question their applicability to psychological science. I conclude that experiential aspects of reality give us reason to remain open to the need for psychological explanation in the treatment of mind.

I suggest that the recent, highly visible, and often heated debate over failures to replicate the results in the social sciences reveals more than the need for greater attention to the pragmatics and value of empirical falsification. It also is a symptom of a serious issue -- the underdeveloped state of theory in many areas of psychology. While I focus on the phenomenon of “social priming” -- since it figures centrally in current debate -- it is not the only area of psychological inquiry to which my critique applies. I first discuss some of the key issues in the “social priming” debate and then attempt to show that many of the problems thus far identified are traceable to a lack of specificity of theory. Finally, I hint at the possibility that adherence to the materialist tenets of modern psychological theory may have a limiting effect on our full appreciation of the phenomena under scrutiny.

Research on future-oriented mental time travel (FMTT) is highly active yet somewhat unruly. I believe this is due, in large part, to the complexity of both the tasks used to test FMTT and the concepts involved. Extraordinary care is a necessity when grappling with such complex and perplexing metaphysical constructs as self and time and their co-instantiation in memory. In this review, I first discuss the relation between future mental time travel and types of memory (episodic and semantic). I then examine the nature of both the types of self-knowledge assumed to be projected into the future and the types of temporalities that constitute projective temporal experience. Finally, I argue that a person lacking episodic memory should nonetheless be able to imagine a personal future by virtue of (a) the fact that semantic, as well as episodic, memory can be self-referential, (b) autonoetic awareness is not a prerequisite for FMTT, and (c) semantic memory does, in fact, enable certain forms of personally-oriented FMTT.

In their critique of Klein (2014a), Trafimow and Earp present two theses. First, they argue that, contra Klein, a well-specified theory is not a necessary condition for successful replication. Second, they contend that even when there is a well-specified theory, replication depends more on auxiliary assumptions than on theory proper. I take issue with both claims, arguing that (a) their first thesis confuses a material conditional (what I said) with a modal claim (Trafimow and Earp’s misreading of what I said), and (b) their second thesis has the unfortunate consequence of refuting their first thesis.

Memory evolved to supply useful, timely information to the organism’s decision-making systems. Therefore, decision rules, multiple memory systems, and the search engines that link them should have coevolved to mesh in a coadapted, functionally interlocking way. This adaptationist perspective suggested the scope hypothesis: When a generalization is retrieved from semantic memory, episodic memories that are inconsistent with it should be retrieved in tandem to place boundary conditions on the scope of the generalization. Using a priming paradigm and a decision task involving person memory, the authors tested and confirmed this hypothesis. The results support the view that priming is an evolved adaptation. They further show that dissociations between memory systems are not—and should not be—absolute: Independence exists for some tasks but not others.

In this paper I argue that radiological attempts to elucidate the properties of self -- an endeavor currently popular in the social neurosciences -- are fraught with conceptual difficulties. I first discuss several philosophical criteria that increase the chances we are posing the “right” questions to nature. I then discuss whether these criteria are met when empirical efforts are directed at one of the central constructs in the social sciences – the human self. In particular, I consider whether recent attempts to map the neural correlates of self and its assumed properties using brain scanning technology satisfy the conceptual conditions minimally required to ask well-formed, theoretically satisfying questions of nature. I conclude that much theoretical work remains to be done.

I argue that our current practice of ascribing the term “ memory ” to mental states and processes lacks epistemic warrant. Memory, according to the “received view”, is any state or process that results from the sequential stages of encoding, storage and retrieval. By these criteria, memory, or its footprint, can be seen in virtually every mental state we are capable of having. This, I argue, stretches the term to the breaking point. I draw on phenomenological, historical and conceptual considerations to make the case that an act of memory entails a direct, non-inferential feeling of re-acquaintance with one’s past. It does so by linking content retrieved from storage with autonoetic awareness during retrieval. On this view, memory is not the content of experience, but the manner in which that content is experienced. I discuss some theoretical and practical implications and advantages of adopting this more nuanced view of memory. -/-