Abstract
The historical representation of natural science as the experimental testing of causal hypotheses with reductionistic, mechanistic explanations has been rightly rejected as an exclusive approach for psychology. However, this representation of science is simplistic and misleading. Interdisciplinary science studies show how biology, physics, and empirical psychology include reflection, empathy, imagination, qualitative analysis, and the creative use of ordinary language in natural scientific practice. Beyond causal experimentation in research and mechanistic explanation in theory, practices across all sciences include intentionality, meaning, holism, values, teleology, temporality, and agency in phenomena. Psychophysical subject matter requires unique methodological norms that interrelate intentional meanings and their external physical, vital, and social realities. Understanding psychology’s complex relation to natural science begs for a closer, more probing, comparative examination of the actual practices of scientists. Only on this basis will methodological norms adequately clarify, justify, and integrate the diverse, pluralistic approach required by psychology’s paradoxical identity.
Keywords
The purpose of this article is to address, from a phenomenological perspective, the general normative question of whether and in what sense psychology ought to be a natural science. I draw primarily on the directives of Husserl, who struggled with the identity of psychology more consistently than any other phenomenological philosopher. Husserl sharply identified the difficulties, paradoxes, and challenges of psychology that remain pressing and are even more complex today than in Husserl’s time. Fresh considerations and new conclusions are needed. First, natural science practices in the 20th century have advanced beyond the representations of science that characterized them in the late 19th century. Second, the diverse developments, extensions, and advances of empirical psychology require more nuanced critiques and conclusions. Third and most fundamentally, because psychology’s subject matter essentially includes consciousness, physicality, and relations with the surrounding world, it requires foundational theory, methods, and factual knowledge that reflect this complexity. Husserl himself held that psychological science must investigate and interrelate causality and meaning with empirical advances beyond the propaedeutic foundations he provided during his lifetime. Original normative work is now needed to show whether and in what sense psychology is and ought to be similar to and/or different from other sciences.
First, I focus on the historical context of phenomenology, specifically the work of Dilthey (1894/1977) and Brentano (1874/1973), who seminally addressed the problems of psychology’s identity in comparison to natural sciences. In Husserl’s (1925/1977) view, they offered sound criticisms of psychology as a natural science as well as clarifications of the characteristics of psychological subject matter that require a different approach. Second, I focus on Husserl’s (1954/1970a, 1925/1977) original contribution to the understanding of natural science and to the theoretical and methodological foundations of psychology as a human or personal science. Third, I review the work of Giorgi (1970), who more than any other psychologist, has compellingly criticized natural science psychology and developed the alternative of human science psychology based on phenomenology. Fourth, I consider several equivocations and complications that challenge historical and still-common representations of physical, biological, and psychological sciences. Finally, based on the insights of phenomenology, I suggest the need for renewed study and innovative problem solving of psychology’s identity and relations to other sciences.
Philosophy is concerned with all that exists (ontology), how we know it (epistemology), and values (axiology, including best-practice norms). That discipline has been interested in the sciences since their origins in antiquity and in modernity. Phenomenology emerged in the 20th century as a critical response to and an extension of modern science. Phenomenology has provided foundational methods, theories, and research in over 40 sciences, humanities, and professions in dozens of countries the world over (Embree, 2010). The present focus is primarily on how phenomenology has contributed to psychology as a science, including psychology’s peculiar closeness to philosophy and relations with other disciplines that feature personal experience. Beyond previous treatments of this topic (Wertz, 1995, 1999, 2023a, 2023b), this article explicitly utilizes the phenomenology and science as a communal practice of free, critical reason; inventive procedures utilizing reflection, empathy, and imagination; democratic, communal structure; justification by evidence; and intrinsically inadequate therefore requiring historical progress (Husserl, 1989a).
In founding phenomenology, the mathematician and philosopher Edmund Husserl gave no positive science as much attention as psychology because it shares with philosophy an interest in consciousness and, as a positive (empirical) science of mental life, is implicated in all other disciplines that require knowledge of lived experience. In his seminal opus, the Logical Investigations, Husserl (1900–1901/1970b) called his method “descriptive psychology” and acknowledged throughout his career that his own way into phenomenological philosophy was through psychology. Although Husserl crucially differentiated transcendental philosophy (the investigation of how the objective world and scientific validity is subjectively constituted) from empirical psychology (the investigation of facts concerning mental life), his conviction that psychology is the crucial discipline in the family of sciences led to his continuing efforts to clarify the proper methods and identity of psychology. In Husserl’s view, the empirical psychology of his day was so riddled with fundamental problems as to be an invalid pseudoscience that could offer genuine knowledge of its subject matter only after radical reform. Its basic error was to exclusively import the views of natural (material) scientists rather than to use original theory and methods based on its own psychological subject matter. Husserl’s foundational theory and methods that faithfully reflect lived experience have had profound implications for and generativity in psychology and other sciences over the last 125 years.
Phenomenological philosophy of science: The distinctiveness of psychology
When psychology was founded as an empirical science, there was explicit consideration of its identity. Science was understood as the employment of “the scientific method”—the experimental investigation of measurable cause–effect relations among variables, and there was critical discussion about the applicability of that method. The founders of psychology—Wilhelm Wundt and William James—viewed psychology as closely related to philosophy and used laboratory methods from the natural sciences as well as other methods suited specifically to psychological processes. In the late 19th century, philosophers Dilthey (1894/1977) and Brentano (1874/1973) doubted that natural science could achieve valid knowledge of mental life and argued that mental and physical phenomena require different concepts and methods.
Husserl (1925/1977), a student of Brentano who encountered Dilthey’s writings after he had formed his own understanding of psychology, was astonished by the incisiveness and profundity of both philosophers’ views. Husserl viewed science—the free-thinking, critical, democratic knowledge acquisition based on evidence—as the ideal way of acquiring knowledge across all disciplines, including philosophy. 1 He understood the great attraction of natural (physical) sciences given their dazzling, far-reaching success in research, theory, and applications. He acknowledged the potential extension of natural science into psychology, given the psycho-physicality of the human—the intrinsic connections of lived experience with its physical body and surroundings. However, he viewed consciousness, also irreducibly present in psychological phenomena, as posing a problem for natural science and for the philosophy of science. His critical analysis of natural science as a universal philosophy led him to reject “naturalism” as a foundation for psychology. 2
Dilthey (1894/1977) argued that because physical phenomena are external to experience and to each other, they require explanation by means of causal inferences. In contrast, experiences are immediately given (therefore require no inference) and entail internal relations of meaning rather than efficient causality. In his well-known dictum, whereas we explain nature, we understand experience. Although nature requires mechanistic, causal explanation by inferential analysis, mental life requires understanding (Verstehen) by description and holistic analysis. Brentano’s (1874/1973) crucial contribution was his insight into the fundamental, defining property of experience that is not found in physical phenomena: intentionality. Whereas physical phenomena reside within themselves and causally (externally) affect other self-enclosed physical entities, consciousness has the distinctive internal, relational property of transcending itself, of being conscious of something (other than consciousness) within itself. Consciousness is therefore not an object but an act that posits objects, for instance in perceiving a chair, thinking 2 + 2 = 4, imagining a unicorn, or remembering a deceased relative. In Husserl’s view, the validity of a science requires fidelity to and evidence of its subject matter. Each science’s theories and methods ought to be based on the distinctive characteristics of and ways of knowing its phenomena. 3 Although Husserl (1925/1977) greatly admired Dilthey’s and Brentano’s intuitive insights into psychological subject matter, he lamented their failure to explicitly delineate rigorous scientific methods to genuinely investigate experience.
From universal science to psychology
Husserl held science in the highest esteem and rejected the speculative claims and pseudoknowledge imposed by authorities and societal conventions without any critique of evidence. Although he shared with naturalistic philosophy the aspiration of universal science, he did not identify science with any particular method. He embraced the more radical and general scientific ideal of methods and knowledge that are free from prejudice, impositions by authority, and established conventions (Husserl, 1989a). This aspirational norm of free, critical, and democratically organized pursuit of knowledge based on evidence is the basis of Husserl’s criticism of naturalism, which is limited to investigation of the physical world. He sought a science that could include everything, including consciousness in all its diverse manifestations. Science itself essentially includes consciousness even though naturalism is blind to it. Husserl, viewing philosophy as a rigorous science, developed methods to investigate logic, mathematics, natural science, cultural objects such as books and paintings, and fields such as politics, economics, and religion. Rather than subtracting or putting aside subjectivity, he abstained from judgments about the existence of objects independent from consciousness and focused on consciousness itself—the perceiving, remembering, imagining, anticipating, thinking, problem-solving, even behaving, and so on. This reflection revealed the directedness of consciousness—its intentionality, its property of self-transcendence, and that included the meanings, values, and purposes of its objects, including those in the physical world.
Husserl investigated the way consciousness apprehends the world, including its physicality and other kinds of objects. He studied intentionality in its various forms—how the objective world is subjectively constituted. Objects are apprehended and illuminated by consciousness, which has the inexplicable yet undeniable property of transcending itself in its directedness to the world, in both everyday life and science. Evidence for intentionality is absolutely accessible in every instance and every moment of consciousness. Reflection immediately shows the directedness of consciousness to objects—to blue, sour, a chair, a headache, a unicorn, a triangle, a mathematical proof, microscopic bacteria, a diagram of the solar system, a psychophysical law, a hallucinated command, a guardian angel—to the world in its utterly inclusive entirety. Psychology is a very special science because every instance and kind of consciousness not only constitutes objects but is performed concretely by a person who is a part of the world—embodied, social, positioned in time and space, and capable of being studied as both a subject and an object. Husserl (1925/1977, 2023) therefore advocated a nonnaturalistic psychology with a method for studying persons that could offer nonreductive knowledge that includes both the person’s subjectivity and situated worldliness. He called the concrete, descriptive, and holistic personal science phenomenological psychology, linked theoretically on the one hand with scientific philosophy and on the other hand to the various mental and cultural sciences that empirically focus on worldly phenomena in which subjectivity is essentially embedded.
Based on his investigations into mathematics and logic (Husserl, 1900–1901/1970b) and eventually his transcendental philosophy (Husserl, 1913/1962), Husserl (1925/1977) articulated methods required for the scientific investigation of consciousness that contrast with the methods of natural science. He differentiated natural and psychological sciences based on the essences of their respective ontological regions. Husserl distinguished formal, exact essences, such as those involved in such mathematics (arithmetic and geometry), from morphological essences, which are inexact. Whereas formal exactitude of measurement and quantitative analysis could be fruitfully applied to physical phenomena in a virtually universal mathematization of nature performed by the natural sciences, the morphological phenomena of mental life require inexact, qualitative ideation and ordinary language to delineate their general kinds, variations, and relationships (Husserl, 1913/1962, 1954/1970a; Wertz, 1995). Husserl identified, meticulously described, and analyzed the two fundamental methods necessary to access mental phenomena: reflection on one’s own experience (based on recollection of lived experiences) and empathic understanding of others’ experience (based on the perception of their verbal and nonverbal expression). 4 Although reflection and empathy differ in that only reflection is primordial and direct whereas empathy is based on the perception of the other’s expression, each has benefits (and limitations), and they are interdependent and interrelated in knowing lived experience.
Psychological knowledge, based on descriptive data gathered through both reflection and empathy, requires two analytic practices. First, the phenomenological epoché and reduction abstains from any attention to what lies outside (independent of) experience and reduces the investigative field to the purely mental, subjective (with its meanings). This reduction of the field corresponds to the physical scientist’s abstention from focusing on subjective meanings and reducing the investigative field to pure materiality. The phenomenological reduction prepares the way for intentional analysis—the analysis of the correlative structures in which mental processes present the meanings of objects and situations, which generates knowledge of the purely psychological. Second, eidetic analysis utilizing free imaginative variation achieves general conceptual clarification of the essential laws of the structures of mental life (Husserl, 1913/1962; Wertz, 1999, 2010, 2021, 2023a). Husserl’s general claims about consciousness were delineated in his published, demonstrative analyses (e.g., of perception) and extended in painstaking, meticulous research in over 40,000 pages of unpublished manuscripts (Welton, 2002). These concrete, detailed analyses provide essential theoretical knowledge of a full variety of mental phenomena in everyday life and science, including sensation, kinanesthesia, motility, instinct, perception, illusion, memory, expectation, imagination, thinking, language, empathy, self-awareness, decision-making, learning (acquisition/habitualization), and the ego (see Husserl, 1980/2005).
Phenomenological psychology: Critique of the natural science approach
Although psychologists and psychiatrists have generated an extensive and broad-ranging psychological knowledge based on phenomenology (Wertz, 2006), Amedeo Giorgi most explicitly criticized psychology’s philosophical foundations and methodology and advocated for human science based on phenomenology (Wertz & Aanstoos, 1999). Giorgi (1970) established the new notion of approach (in contrast to subject matter and methods) to describe the philosophical and methodological assumptions of psychology. He identified the natural science approach that pervaded psychology since its founding as a science and documented compelling criticisms in every decade since the science’s founding, all traceable to its naturalistic philosophy. Giorgi attributed psychology’s remoteness from life, fragmentation of subject matters and theories, exclusion of important topics, and the persistent gulf between research and practice to psychology’s atomistic, quantitative, and mechanistic natural science approach. To correct these problems, Giorgi (1970, 2000) articulated a human science approach that is descriptive, analytic, and holistic—faithful to psychological life. Since the 1970s, he developed and delineated human science research procedures that entailed the empirical collection of concrete descriptions, comprehensive and systematic analysis, and qualitative knowledge of general structures of psychological life (Giorgi, 1975, 1985, 2009). Giorgi’s work has led to extensive new psychological knowledge (e.g., see Churchill et al., 2021).
Giorgi (2023) recently related a curious notion that he called “the palpable” to the historical effort to establish scientific psychology. Arguing against the continuing empiricist philosophy underlying psychology, he asserted that the experimental method precludes valid knowledge of consciousness inasmuch as it is restricted to causal inference and mechanistic explanation, which exclude meaning. Giorgi explained how Western science, in an attempt to define itself in contrast with speculation, hunches, unfounded beliefs, and religious faith, took sensory experience, in observations and rational analyses, as the only valid evidence supporting knowledge. Whereas natural science rightly investigates the material world that is perceptible through the senses, such disciplines as philosophy, theology, and literary studies lose epistemic validity when they follow a model that excludes consciousness and meaning.
Giorgi (2023) noted that there is much in the world that is not entirely physical, such as laws, paintings, political ideologies, values, and religious faith. To use the natural scientific method to know such matters requires a subtractive procedure, whereby the very subjective and cultural (“supranaturalistic”) aspects of these phenomena are ignored and only their palpability (the “naturalistic”) is investigated. The human being’s nonpalpable aspects must be methodically subtracted when science focuses exclusively on the physical body, the nervous system, and surrounding stimuli. Wundt (1897/1969), with a background in physiology, ingeniously founded the first psychology laboratory at the University of Leipzig in 1879 by viewing sensations, 5 which were used in observations of physical things, as palpable data, thereby extending science to the nonphysical. Wundt used the model of physical science to establish a laboratory in which the experimental method, the gold standard for natural scientific knowledge acquisition, was employed to investigate sensations. Psychophysical experiments were used to study the causal effects of stimuli on sensation, which were thereby considered palpable. Psychological phenomena, such as absolute/differential sensory thresholds and laws of psychophysical causality were established through experimental manipulations, observations, and statistical analyses. Psychologists have been expansive in their use of the experimental method to study less palpable phenomena. For instance, Wundt used reaction time experiments presenting complex stimuli and measuring reaction time (response latency) to infer the duration of unobservable higher mental performances. Wundt (1897/1969) wrote: “As soon as the psyche is viewed as a natural phenomenon, and psychology as a natural science, the experimental method must also be capable of full application to this science” (p. 70). The history of psychology included measurement of even the most impalpable mental phenomena, such as intelligence and spirituality, through widening observations of the palpable (e.g., behavior and test performance).
Giorgi viewed the importance of behavior for psychology as following from its undeniable palpability. He quoted Watson’s (1913/1994) testimony to psychology’s more complete achievement of natural science status by focusing only on behavior: “Psychology, as the behaviorist views it, is a purely objective, experimental branch of natural science which needs introspection as little as do the sciences of chemistry and physics” (p. 176). Giorgi quoted Hilgard to demonstrate the historical importance of laboratory experimentation as the gold standard of psychological methods:
The development of psychological laboratories was a visible sign that psychology had the intention of becoming recognized as a naturalistic experimental science and . . . the importance of the laboratory in attaining acceptance as a science by other scientists cannot be overestimated. (as cited in Giorgi, 2023, p. 202)
Giorgi (2023) insisted that this achievement came at great cost: Psychology became unable to investigate consciousness, exemplified in dreams, thoughts, images, phantasies, memories, and anticipations that are not physical or even palpable in their very essence. What happens even in the perception of a chair remains unknown when one subtracts the intentionality of consciousness and restricts science to observations of the physical world. Giorgi insisted that consciousness itself—with its impalpable intentional relations to the meanings of objects, requires reflection rather than observation of the palpable to access intentional meaning. Psychology must go beyond the philosophy, methodology, and methods of natural science to attain knowledge of psychological realities.
Equivocations: Science as historically dynamic human practice
Despite these strong and compelling arguments, various equivocations arise from the more recent, interdisciplinary field of science studies. Its specific focus on practice offers understandings of science that differ from the representation of natural science found in the work of Dilthey, Husserl, and Giorgi. Studies of the actual practices of 20th-century biologists and physicists complicate our answer to the question of psychology’s similarities to and differences from natural sciences. Below, we return to the question of what natural science is. Science is a human practice, and this practice has exceeded and contradicted the simplistic representations and characterizations that portray human and natural sciences as mutually exclusive. Studies of science have brought to light processes in research that exceed and even contradict the above representation of natural science (and its method) that now appear to be a prejudiced caricature based on a myth and cult that falsifies what scientists actually do. In much education in psychology, science is defined and characterized as employing the method presumed to be employed by physical scientists. Testing hypotheses by such empirical procedures as the true experiment is considered the gold standard. This method achieves knowledge of palpable realities by operationally defining, manipulating (when practically and ethically feasible), and measuring variables followed by statistical analyses that support probabilistic inferences of causal relationships (laws among objectively defined variables). Although this scientific practice has been employed and well documented, it is not the whole story of physical, biological, or laboratory psychological science. Space constraints do not allow a systematic, comprehensive review of the interdisciplinary advances in our understanding of science; in the following I offer a sample representative of works that dispel this myth of naturalism and suggest revisions in our understanding of natural science based on the actual practices of scientists.
Husserl anticipated many of these science studies, which focus on consciousness and personal activities. Although science studies and natural sciences have not self-consciously applied phenomenological methods, they have focused nonreductively on natural scientists’ meaningful, value-bestowing, and goal-oriented experiences of their variegated phenomena. The conception of natural science criticized by Dilthey, Husserl, and Giorgi, still widespread and uncritically accepted today, is derived primarily from the physical sciences (especially physics and to some extent chemistry) rather than life sciences such as biology. It is also limited to a (Newtonian) physics rather than reflective of 20th-century advances. Though reductive, mechanistic physics remains applicable to some important physical phenomena, it has by no means exclusively prevailed in physics, biology, and psychology as they developed in the 20th century according to the new insights of multidisciplinary studies of natural science.
Osbeck et al. (2013) identified an implicit “person-centered” tradition in studies of science, citing Ian Mitroff’s (1974) study of Apollo moon scientists, Mahoney’s (2004) Scientist as Subject, Maslow’s (1966) Psychology of Science and other sources that investigate the lived experience and influence of social relationships on scientists’ reasoning and problem-solving practices. Contemporary philosophers of science such as Nersessian (2022) make use of qualitative methods to investigate scientists in their “natural habitats” (e.g., laboratories), leading to accounts of science rooted in the contexts of practice (including social). In Osbeck et al.’s (2013) ethnographic studies of laboratory work by bench biology and engineering researchers, one interesting and surprising finding was the prevalence of anthropomorphism in representations of cells, which researchers referred to as “happy.” Scientists aimed through both practical and conceptual activities to keep the cells happy. In her study of values in science, Osbeck (2019) depicted scientists’ broad and unconstrained observation, imaginative sense-making, and empathic position-taking as crucial to advances across the sciences. Osbeck and Antczak’s (2022) edited volume investigated great achievements in natural science by focusing on the personal lives, relationships, and activities of such scientists as Kepler, Goethe, Mendeleev, Poincaré, and Boas. Notably, these philosophically informed, nonnaturalistic studies used nonreductive psychological methods to study physical sciences. These studies are complemented by convergent investigations by biologists and physicists, who are both philosophical and psychological, which suggest that although distinct, scientific disciplines essentially overlap. A few examples are provided in the next sections.
Biology
The phenomenon of empathy in observation of extra-causal self-determination in biological phenomena has been crucial to advances in 20th century theory and research (Keller, 2004). Keller viewed these advances as entailing expansive (including feminist) subjective sensibilities of scientists that she insists make science more objective (cf., Harding, 1995). Keller (2004) reviewed phenomena classified as “maternal effects” in fertilization, mutation, and developmental biology, evolutionary biology, and ecology. For instance, the sperm and egg are viewed as “mutually active partners” that “find each other and fuse” (p. 8). The first generation of geneticists (in the 1920s and 1930s) began attributing to the gene an “omni-potency—not only causal primacy but autonomy and, perhaps especially, agency. Development is controlled by the action [emphasis added] of the genes” (p. 9). The notion of “function” is primary; the gene is not only physical but also in part “platonic soul” and “animating force.” The notion of “gene action” became commonplace and has guided immensely successful research for 40 years. In the last 25–30 years, this idea was renewed and transferred “from genes themselves to the complex biochemical dynamics (protein-protein and protein-nucleic acid interactions) of cells in constant communications [emphasis added] with each other” (p. 9). Keller (2016) wrote:
(Cytoplasmic) signals are not restricted to the simple physical and chemical stimuli that impinge directly on the DNA, on the surface of the cell, or even on the body as a whole: organisms with central nervous systems have receptors for forms of perception [emphasis added] that are not only more complex but far longer range. Humans have especially sophisticated perceptual capacities, enabling them to respond to a wide range of complex visual, auditory, linguistic, and behavioral/emotional signals in their extended environment [emphasis added]. Research has recently begun to show that responses to such signals can extend all the way down to the level of gene expression. The question is this: To what extent are we witnessing (at last) a rapprochement between the natural science of Biology and the human sciences of Sociology and Anthropology [emphasis added], and to what extent do the new promises of synthesis merely reflect an expansion of older reductionisms, threatening once again to marginalize rather than incorporate the insights of cultural analysis?” (p. 26)
Biologists are interested not only in relations between behavior and the proximal environment but in more distal relations of “signals” and perception proper, along with a functional emphasis on meaning. The above reference to the organism’s distal relations may be seen as entailing the phenomenon of “intentionality,” characteristic of consciousness according to Husserl (1989a, 1989b), who viewed animals and possibly even plants as conscious “persons” to be studied by means of the personalistic (in contrast to the naturalistic) attitude.
Biology’s differences from physics and chemistry, both in theory and method, are based on the objective reality of its subject matter. Von Bertalanffy (1969) suggested that although physical laws such as those of thermodynamics could be validly applied to “closed” systems, living things and biological phenomena are “open systems.” In 1934, he developed an individual growth model that led to a general systems theory that replaced reductionism with holism and placed organism over mechanism (von Bertalanffy, 1969). More recently, feminist biologists have emphasized the importance of empathy in accessing biological phenomena, for instance in the Nobel Prize-winning work of Barbara McClintock (Keller, 1983) and more generally in 21st-century biology (Ney, 1999). Ethology includes behavior, both innate and learned, and views animal life not only in its proximate, causal mechanisms but as embedded in and adaptive to larger environmental systems understood holistically in functional activities of all species. Earlier paleontologist Teilhard de Chardin (1999) bridged gaps of the sciences as physics, biology, psychology, and theology in his postulation of meaning (a noosphere) and teleology (an omega point) not only in biological evolution, from the simplest unicell organism to the human, but in subatomic physical phenomena and processes (cf. nonreductionist science in Polanyi, 1968, 1970).
Physics
The physical sciences, as they encountered new phenomena, have moved beyond theory that exclusively posits causal mechanisms by using experimental methods. Physics developed beyond Newton’s theory of gravity and classical conceptions of efficient causation (Rohrlich, 1989), which was replaced by the notion of “field” as early as Faraday’s 1845 investigations of electricity (Faraday, 1846) and later in Maxwell’s (1865) research on electromagnetism. In the 20th century, Max Plank’s studies of the atom (including subatomic particles) and blackbody radiation led to quantum mechanics, in which Einstein, Bohr, and Heisenberg highlighted the observer as integral in physical phenomena (Griffiths & Schroeder, 2018). Berghofer (2023), a phenomenological philosopher, traced the development of quantum physics, in particular QBist views of quantum mechanics and science, which focus on the relationship between the experiencing subject and the experienced world. The inclusion of experience in physics led Berghofer to call for changes in Husserl’s assumption that physicists methodically put subjectivity out of play, subtract meanings, and abstract the physical world. Berghofer showed how physics has rejected the notion of a purely objective world and has introduced first-person subjectivity in physical science. Whereas from the 17th century to the early 20th century, classical mechanics was the most successful scientific theory and shaped our representations of the world and science, 20th-century quantum mechanics has recognized even in the fundamental activity of measurement a human activity that relates ideation to material (nonmathematical) phenomena, essentially including the observer as a subjectively engaged performing agent. Such leading physicists as Bohr and Heisenberg insisted that quantum physics requires a break with the objectivist view of the world that is still so prevalent in physics and science education. Berghofer even documented the superior predictive power of physical science that does not merely investigate an objective world but utilizes the experience of physical phenomena. Viewing the “wave function” as a mathematical tool that encodes one’s expectations about future experiences, contemporary QBism in physics applies a personalistic, Bayesian account of probability to quantum phenomena that features degrees of belief about the future. The methods of quantum physics, and science more generally, are not limited to an objective description of reality-in-itself; rather, they fruitfully include subjectivity—the agentic experiences of scientists in connection with their physical phenomena (Berghofer, 2023).
In viewing science as a sense-making systematization of experiences, neither philosophical physicists (QBists) nor Berghofer rejected metaphysical realism or subscribed to instrumentalism, idealism, subjectivism, constructionism, or solipsism. On the contrary, philosophical as well as theoretical physicists have characterized physics as the tool whereby we systematize our experiences to offer knowledge about the real world. Berghofer’s (2023) main thesis concerns science itself, that we learn from the most successful physics—quantum mechanics, that physical scientists do not, nor should they abstract away from and thereby eliminate the subjective. Although classical mechanics was and remains successful in many empirical domains, it fails in other contexts, lacks generality, and no longer serves as the superordinate physical theory. Quantum physics succeeds better and is more universally applicable in physical science by means of its explicit acknowledgment and inclusion of subjectivity. For Berghofer, modern physics has abandoned an outdated and misleading notion of science that was drawn from an early history and surpassed in the 20th century. He advocated abandoning metaphysical hypotheses (assumptions about the ultimate nature of reality) in favor of the actual historical achievements of science, which in physics opposes the philosophical prejudices of naturalism.
Psychology
There is little doubt that psychology eschewed philosophy in history when it identified itself as a science by importing theoretical and methodological guidance from the physical, natural sciences. Psychology’s identity as a science modeled after natural science has been central to its societal success, proliferation, and self-esteem. Nowhere is this clearer than in psychology’s research methodology. Introductory textbooks and much of the curriculum characterize psychology’s “scientific method” as hypothesis testing that requires the operational definition and measurement of variables followed by statistical analysis that provides evidence in support of inferences. Psychology still operates with an implicit methodological hierarchy despite increased openness toward a range of methods. The true experiment, in which independent variables are manipulated and dependent variables are measured, is viewed as the gold standard and ultimate sin qua non of research because it supports causal inference, and specification of mechanisms (Lilienfeld et al., 2017). Since not all variables can be manipulated due to practical and ethical constraints, quasiexperiments and correlational research, which also engage measurement and statistical analysis, are viewed as the next best methods, followed by such less esteemed methods as survey and naturalistic observation that ideally involve measurement. There is no mention of procedures or methods uniquely based on the distinctive characteristics of the mental as such. References to experience and to reflection and empathy as fundamental modes of access to psychological evidence proper, are not included. Quantification is highlighted, and if qualitative methods are mentioned at all, they are presented as secondary, at the bottom of the methodological hierarchy lacking intrinsic value, philosophical support, and methodological rationale. This approach has remained identified with “empiricism” and contrasted to “pseudoscience” (Lilienfeld et al., 2017), even after compelling criticisms and arguments that this view of science is an untenable prejudice, ideology, social convention, and even cult (Danziger, 1994; Toulmin & Leary, 1985).
Although one might conclude that psychology has been carried out according to the above representation of science, closer investigation leads to the conclusion that extant psychology, as actually practiced, is not exclusively or even best understood as it represents itself. Gergen (1994) compellingly argued that the merit and impact of the best-known and influential social psychological experiments rests not in experimental procedures but on their moral narrativity. Guntrip (1973) characterized Freud’s accomplishments as bidirectional, as a natural and personal, object–relational science. He documented how, within Freud’s career and the larger history of psychoanalysis, advances have followed the abandonment of the natural science orientation and the employment of a nonreductive, interpersonal, and relational approach that features meaning. This view has been supported, further articulated, and extended in a series of works that identify the implicit, operative practice of phenomenological methods in psychoanalysis (Wertz, 1986; Wertz & Olbert, 2016). Moreover, a largely unrecognized history of qualitative practices, even among psychologists known primarily for natural science methods, has not only been documented in the work of such seminal researchers as James, Flanagan, Bandura, Kohlberg, Maslow, Simon, and Kahneman (Wertz, 2014) but has been the driving force in the most significant advances in 20th-century psychology, such as the behavioral, humanistic, and cognitive revolutions (Wertz, 2023a). For instance, the 20th-century advances from the reflex to instrumental, operant, cognitive, and social learning show increasing focus on the distinctively psychological. For example, even as it represents itself as a natural science that excludes consciousness, Skinner’s (1974) radical behaviorism features psychological processes that are not reducible to physical phenomena, for instance, inasmuch as environmental reinforcement and punishment are defined by their behavioral consequences, not material properties. The investigation of practices implicit in historical advances toward the uniquely psychological suggests that phenomenological methods, which have been found to be operative in virtually all qualitative inquiry in psychology (Wertz et al., 2011), are essential in psychological research, which is nonreductive at its best. Person-centered, existential practices, demanded by psychological subject matter and normatively foundational in psychological science, have been found even in advances that have been represented as the most extreme implementations of psychology as a natural science (Wertz, in press). Psychology has, in its best practices, not exclusively followed a simplistic model drawn from natural science even though it is still being represented and taught as such to generations of students.
The methods of psychology have developed in many directions beyond hypothesis testing by means of experimentation, and leaders have highlighted alternative philosophical frameworks. For example, the quantitative methodologist Rodgers (2010), in reporting on the epistemology of the “quiet revolution” of mathematical modeling in psychology, was highly critical of experimental research and statistical analysis even though they are still extensively favored. Contemporary psychology shows complexity, nuance, and continuing controversy as normative considerations about psychological research methods change and evolve. Natural science is not best understood exclusively by the restrictive representation of science that is so pervasive in much of psychology’s curriculum, and the actual practices that have advanced psychology entail methods not based on that model.
Methods have developed in silos without any clear understanding of an overall methodological normativity that offers principles for weighing the various forms of evidence utilized in disparate research methods. For instance, the important question of scientifically establishing effective psychotherapies has been riddled by controversy over methodological normativity. The notion of “empirically validated” psychotherapies, proposed in the 1990s and still implemented today by strictly experimental methods modeled on randomized, controlled trials of pharmaceutical research in medicine, gave way to evidence-based practice early in the new century (APA Presidential Task Force on Evidence-Based Practice, 2006). Twenty-first century APA policy characterized practice norms as standing on three legs: psychological science, the practitioner’s expertise, and the patient’s personal and cultural meanings, values, and goals. The first leg explicitly includes heterogeneous scientific knowledge that utilizes multiple methods, ranging from the experiment to the case study and from measurement to narrative. Policy makers found no agreement among legitimate expert psychological scientists about how to weigh the evidence based on disparate scientific methods (APA Presidential Task Force on Evidence-Based Practice, 2006). On the one hand, the APA approved clinical “treatment guidelines” based exclusively on “systematic reviews”—experimental research based on the medical model, and on the other hand APA approved “practice guidelines” that emphasize personal and cultural subjectivity in a two-way collaboration between psychologist(s) and patients, whose goals, values, and meanings are considered primary in clinical decision-making and services. APA’s policy has provoked continuing disagreement, given its lack of specificity concerning how the three legs of evidence-based practice ought to be related to each other—how various kinds of scientific knowledge are to be integrated and interrelated with clinical expertise and patients’ personal interests. Psychological science and professional practice remain fraught with controversy and challenges that beg for renewed resolutions of a unifying methodological normativity for psychological science. It is ironic that psychology, as the science of mental life, has still not broadly acknowledged and institutionalized a science of personal life that offers comprehensive, reflexive, and integrative knowledge of psychology itself as a human practice.
Contributions of phenomenology
Phenomenology can contribute more centrally to science studies and to our understanding of psychology by offering a method that sets aside prejudices and prior concepts, describes concrete practices including the consciousness of scientists, and explicates their essences. Phenomenology offers two kinds of resources for developing a cohesive normative framework within which multiple methods are cohesively interrelated and integrated. First, as a descriptive method for studying human activities, phenomenology can help clarify and compare the practices of psychological researchers of all the various stripes, as philosophers of science and cross-disciplinary science scholars have done across other sciences. Descriptive science studies promise to provide a more accurate view of how psychological science is actually practiced and can surmount the limited and misleading representation offered by textbooks that confine research to hypothesis testing and mechanistic explanation. Comparative analysis based on descriptive understanding of psychologists’ actual practice can contribute new understandings of both commonalities and differences across various kinds of psychological research. Second, phenomenology offers a critical framework for assessing the relative closeness and remoteness of research to psychological phenomena as evidenced in concrete reflection and empathy. The major problem to be addressed by a comprehensive normative framework is the role and relationship of quantitative (and other) inferential procedures with concrete, intuitive knowledge of psychological subject matter in the lives of persons. Phenomenology acknowledges the potential value of inferential methods and theories in relation to what is concretely given in personal lived experience. 6 Phenomenology thereby offers a philosophical evidentialism in knowledge that is in principle consistent with psychology’s policy of evidence-based practice, which also prioritizes the meanings, values, and goals of persons as a ground of psychological normativity. Through its unprejudiced description and understanding of scientific practices, phenomenology provides a framework in which multiple methods ranging from those that generate abstract inferences to those that concretely describe personal life are interrelated as required by the essence of psychological life itself. On this basis, the value of each method and its type of knowledge can be clarified. Best practices can be cohesively related and delineated based on the quality of their evidence in psychological subject matter. Such a normative framework is an aspiration, not currently available. Psychology will reduce fragmentation and better clarify its disciplinary identity by means of increasing reflexivity and philosophical and methodological grounding.
Conclusion
Since its beginnings, phenomenology has attempted to ground scientific knowledge in epistemology and ontology, that is, to clarify the required and best ways of knowing the physical, vital, psychological, and spiritual based on what they are. As sciences have developed through the 20th century, all have forged new ways of knowing that reveal previously unknown aspects of their subject matters. The question of whether psychology is or should aspire to be a natural science is complicated by these newly emergent understandings of how natural science is practiced. Much that has been assumed about natural science, among both advocates and critics of its value in psychology, appears to be an overly simplistic and restrictive representation. The commonly held view, which continues to privilege experimental methods and causal explanation, does not adequately reflect the actual practices in biology, physics, and natural science psychology as they have developed through the 20th century. This stereotype of natural science is outdated. Inquiry into the complex practices of scientists offers a more adequate understanding. Science does not and ought not conform to any one model of method. Progress is made through critical, free, and pluralistic thinking; equity and dialogue among members in an open, inclusive community; evidence as the court of appeal in justifying knowledge claims; and unending historical renewal as scientists strive for more adequate knowledge (Husserl, 1989a). Within that broad framework, recent studies of practice highlight various kinds of observation, imagination, empathy, reflection, ideation, thinking, and communication—human activities that are practiced across all sciences. Science advances by overcoming ideology, authority, social pressure, rigid conformity, and all forms of conceptual and social prejudice.
The highly general normative structure of science outlined above does not mean that psychology is the same as other sciences. Each science has its own unique subject matter. Psychology faces the distinctive challenge of a subject matter that is paradoxically both subjective and objective. To grasp the subjective, psychology requires methods that suspend objectivity on the one hand and incorporate it on the other hand (Husserl, 2023; Wertz, 2023b). Psychology requires methods that focus on the essential structures of individual persons’ mental life as well as the factual variations of aggregated populations of diverse individuals. Psychological measurement that integrates observation and formal ideation of mental life is different from measurement in physics and sciences of nonpsychological subject matter.
What distinguishes psychology across its many traditions and goals is its subject matter—psychological life, which includes lived experience in its relations to biological, physical, and cultural phenomena. Psychology’s overlaps with other disciplines, not only physical and biological sciences but humanities (philosophy, theology, literary studies), social sciences (sociology, economics, anthropology, history), and arts (literary, graphic, and performing). Such overlap and complexity by no means preclude the delineation of psychology’s uniqueness and unity, they make it all the more imperative. There is no way around the distinctive demands of mental life (consciousness, subjectivity, whatever name is adopted) and the relations with the surrounding physical, social, and cultural world that are equally essential. Psychology therefore requires both understanding and explanation, knowledge of meaning and causality, and description and inference to achieve a principled, coherent, and comprehensive methodology, even if it remains to be articulated in practical detail. Psychology requires multiple methods with critical, reflexive employment in light of their purposes, limits, and systematic function in relation to the realities of personal experience. To be grounded in concrete, intuitive evidence as all science requires, psychology must fundamentally include reflection and empathy as touchstones with the realities of its subject matter. Measurement of personal experience and related subject matter that entail intentionality and meaning poses unique problems because what is measured is not limited to physical things, or “things” (objects) at all. Qualitative analyses of what is paradoxical, mysterious, and can never be known in a fully adequate way is foundational. A phenomenological clarification of the meaningful, value-laden, and purposive structures of mental life in ordinary language can be synergistically integrated with nonphenomenological methods that focus on objective realities—physical, biological, social, and cultural surroundings, which are intrinsically related theoretically and empirically to the pure structures of lived experience. However, without being genuinely and rigorously related to personal life, psychology falls short of the realities of its subject matter.
Understanding how the psychological is related to the biological, physical, and cultural in the variegated complexities of the empirical world requires renewed normative elucidation of psychological methodology. Psychologists have been limited in their capacity to address foundational questions about their science’s unique identity by the pervasive naturalism and inadequate education in philosophy, the history of science, and critical, comparative methodology. Fresh descriptive understanding and normative thinking about best practices require continuing humility and open inquiry into psychological science.
Footnotes
Funding
The author received no financial support for the research, authorship, and/or publication of this article.