Beyond Standard Diagnoses: Biosemiotics, Symbol Theory, and the Subjective Lifeworld in Neurology, Psychiatry, and Psychotherapy

Abstract

Standard diagnostic categories (International Classification of Diseases (ICD) and Diagnostic and Statistical Manual of Mental Disorders (DSM)) were developed as a pragmatic compromise between competing theoretical schools in psychiatry and psychotherapy. Focused on recognizable patterns of symptoms, they produce reliable descriptions and facilitate clinical communication, research, and reimbursement. Such a focus, however, necessarily falls short of the etiological complexity of bodily, personal, interpersonal, and cultural processes that shape human suffering. This article argues that beneath the diversity of approaches seeking to address this gap, a fundamental complementarity emerges—one constitutive of human existence itself: the complementarity between two irreducible ways of being in the world. The first is the organismic–biological dimension, elaborated in Jakob von Uexküll’s biosemiotics: sign-governed, evolutionarily pre-formed processes of meaning-attribution that operate prior to and independent of language. The second is the symbolic–cultural dimension, developed in Ernst Cassirer’s philosophy of symbolic forms: the embedding of human beings in socially created, intersubjectively shared symbol systems through which the world is seen and understood. Although both approaches were published nearly a century ago, this article is not primarily a historical contribution. Rather, it argues that psychopathology and therapy can be understood more fully—and clinical practice enriched—when both dimensions are taken into account as genuinely complementary perspectives.

1. What Standard Diagnoses Cannot Capture

In clinical practice across neurology, psychiatry, and psychotherapy, the moment a patient receives a diagnosis—depression, borderline personality disorder, conversion disorder, schizophrenia, etc.—something both necessary and conceptually troubling occurs. A name is assigned to a cluster of observable signs and reported symptoms. Administrative systems are satisfied. Treatment pathways open. Reimbursement becomes possible. Clinical research, too, benefits from the reliability of the categories thus created. And yet experienced clinicians are often dissatisfied with the fact that the selection of signs declared relevant in this way fails to capture much of what their years of expertise lead them to regard as important. The diagnostic labels say little, for instance, about the particular person sitting across from them—their way of inhabiting their world, the specific texture of their suffering, and the meaning this suffering holds within their biography and relationships.

ICD and DSM systems work, as is well known, by identifying symptom clusters that co-occur with sufficient frequency to warrant a name. They are descriptive and statistical tools, not etiological accounts. Their reliability across observers and contexts is purchased at the cost of validity with respect to the complexity of each patient’s life dynamics. This reductive selection, however, did not occur because clinicians overlooked the full range of observable signs. Rather, operationalized, criteria-based definitions—and the very concept of “disorder”—were introduced in DSM-III in 1980 as a pragmatic compromise between competing theoretical schools: psychoanalytic, biological–psychiatric, and behavioral. The primary aim was to avoid any commitment to etiology and the controversies that would accompany it.

This step enhanced diagnostic reliability. But the cost was high: complex life histories were reduced to symptom clusters; suffering was decontextualized from its social, biographical, and relational matrix; and what the patient experiences—as distinct from what the clinician observes—was systematically marginalized. Nancy Andreasen, one of the original initiators of DSM-III, had in fact aimed with her working group to reactivate phenomenological perspectives and refocus attention on the patient as a person. According to Andreasen [1], this aim was turned into its opposite. She argues that the powerful internal momentum of these systems forces physicians and psychologists to adapt to the reduced categories of DSM and ICD, rather than allowing them to focus on a broader spectrum of signs and on the lived experience of their patients.

As a consequence, the two current major classification systems—DSM-5-TR (implemented 2022, APA) and ICD-11 (implemented 2022, WHO)—are praised for several advantages: they improve reliability between clinicians, facilitate communication and research, enable epidemiological studies, and support healthcare administration and treatment planning—within the limits of this approach. However, the extensive critical literature on these systems has questioned not only their limited biological validity—neither specific biomarkers nor unique genetic signatures have been identified—but also the value of their high reliability. This reliability, critics argue, is more artificial than clinically substantive: many patients meet criteria for several disorders simultaneously (high comorbidity), while patients with the same diagnosis can present very differently (diagnostic heterogeneity).

For the purposes of this article, two other points in the critical discussion are more directly relevant. If one takes seriously the many signs and symptoms observable in clinical practice—signs that lie beyond what standard diagnostics capture—there are good reasons to situate human suffering within a complex web of bio-psycho-social processes. Engel [2] proposed a model for such an extended perspective half a century ago, which has gained worldwide recognition under the label “bio-psycho-social”: psychic distress is to be understood as a partial process within a larger, multi-layered dynamic. What moves to the center of clinical attention is then not only symptoms that are objectively identifiable and quantifiable. Equally important are the complex relationships that human beings have with themselves (including their somatic processes), with others, and with their world. And this means attending not only to the signs and meanings that clinicians assign to what they observe in their patients—but equally to the signs and meanings that patients themselves assign to inner and outer events in their lifeworld.

Taking these meanings into account is, however, more difficult than it might initially appear. Patients, like all human beings, often speak about themselves in “borrowed” language: in the diagnostic labels absorbed from the healthcare system, in the narrative frameworks of their family culture, or in the evaluative categories of their social environment. These “introjects” may overlay and distort the organismic experience they purport to describe. What the patient says about themselves is not the same as what they experience. And what they consciously experience is not the same as what is occurring at the organismic level. Clinical practice would need to address all three layers—a challenge for which symptom-based classification provides no tools, and for which the other approaches briefly discussed below have not yet found satisfactory solutions either.

This article does not—and cannot—offer a path toward a diagnostics that satisfies all these concerns, nor toward a therapeutic practice fully built upon it. The arguments presented here do not form a closed system. They constitute a polyphonic argument that respects the complexity of the subject. What this article does aim to do is to draw attention to a complementarity that, in our view, underlies many of the debates on these questions without being made explicit: the complementarity of the two ways in which we human beings are in the world and structure it with meaning. The first is through long-underestimated formative processes rooted in evolutionarily pre-formed organismic structuring principles—something we share, in similar specific ways, with the animal world. The second is through equally underestimated formative processes rooted in participation in socially and culturally created symbol systems—systems through which we see and (more or less consciously) understand the world, and which are specific to human beings alone.

Two intellectual traditions provide the conceptual foundation for this orientation. The first is the biosemiotics of Jakob von Uexküll [3], which has clearly articulated the organismic–bodily perspective. The second is the philosophy of symbolic forms of Ernst Cassirer [4], in which the symbolic–cultural dimension is developed as a central perspective. When these two approaches are discussed in some detail in what follows, the aim is not primarily historical reconstruction. Rather, it is to show that the two complementary modes of human existence are most clearly distinguished in these foundational texts—whereas in later and contemporary discourse they have been brought together to varying degrees, which has opened up creative possibilities for re-examination but has also blurred the clear distinctions between them.

2. The Organismic Perspective: Biosemiotics, Umwelt, and the Social Brain

At first glance, the question of how a living organism relates to its environment seems to belong to biology rather than to clinical psychology or psychiatry. Yet the answer to this question has far-reaching implications for how we understand perception, emotion, symptom formation, and the limits of diagnostic classification. Jakob von Uexküll (1864–1944), who worked as a biologist at the University of Hamburg in the early twentieth century, introduced a distinction that is deceptively simple but conceptually fundamental: the distinction between Umgebung and Umwelt.

Umgebung refers to the objective physical world as neutral observers might describe it: the totality of stimuli, objects, and events present in a given space. Umwelt, by contrast, is the world as a specific organism actually perceives and acts within it. The Umwelt is determined by that organism’s particular sensory and motor capacities. The meanings it assigns to elements of the surroundings are generated by those capacities. Consider a summer meadow: it is a single Umgebung shared by ants, bees, frogs, and cattle. But each species inhabits its own Umwelt. The category “ant” or “frog” exists only in human textbooks. For each animal, only certain features of the environment and of other animals carry meaning. And these meanings are sign-governed, not stimulus-driven [3]. Through its receptors, an organism takes up signs from its surroundings—von Uexküll calls this the Merkwelt (perceptual world). Through its effectors (e.g., limbs), the organism acts upon the surroundings—he calls this the Wirkwelt (action world).

This emphasis on sign-governed meaning—understanding the organism as an active interpreter rather than a passive respondent to stimuli—has direct clinical implications. The classical stimulus-response model assumes that organisms respond to the objective physical configuration of their environment. Biosemiotics argues that this is fundamentally mistaken. What organisms respond to are signs: features of the surroundings to which their biological architecture—especially the nervous system—assigns functional significance. This process of meaning-attribution is not learned but evolutionarily pre-formed. It is constitutive of the organism’s way of experiencing and inhabiting its world. This understanding is also relevant to current debates in biosemiotics [5,6].

For clinical practice, this has a clear consequence. A patient’s response to a given situation—a tone of voice, a spatial arrangement, a pattern of gaze, or indeed a prescribed intervention—cannot be read off from the objective properties of that situation. It must be understood from within the patient’s Umwelt: from the meanings that their organismic history has deposited in these features. In the field of medicine, this was further developed by Thure von Uexküll [7,8].

A simple feedback loop between Merkwelt and Wirkwelt is, however, an inadequate model for most living beings. In the course of evolution, an increasingly elaborate “new circuit” was interposed between receptors and effectors—realized primarily through nervous systems, which integrates and coordinates information from multiple sensory organs and thereby greatly extend the organism’s capacity to survive in its surroundings. Crucially, this integration enables organisms to form what Mausfeld [9] calls “suprasensory” or “transensory” meaning-categories: categories arising not from any single sense organ but from the integration of multiple sensory streams. Heat, brightness, loudness, pitch, and pressure are, for example, categories of individual sense organs. But “food”, “predator”, “mate”, “edible”, and “dangerous” are meaning-categories that rest on evolutionarily developed interconnections among sensory organs within the architecture of the nervous system—and, importantly, they do not rest on reasoning or inference in any narrow cognitive sense.

In human beings, the range of such suprasensory categories is vastly expanded. Contemporary infant research has progressively mapped the extraordinary scope of these evolutionarily pre-given categories. Newborns display differentiated responses to certain “possible” versus “impossible” physical events [10]. But far more salient for infants are categories of the social world: animate versus inanimate objects, causal versus intentional events, and concepts such as “threat”, “fairness”, “causation”, and “animacy” and proto-social stimuli of many kinds [11]. Infants scan their environment for patterns in language and in the support behavior of caregivers, thereby fill in pre-formed structures with the concrete rules of grammar and of attachment behavior. These findings support the concept of the “social brain” [12]: human cerebral architecture is primarily an organ for navigating the social world, not for coping with the physical environment [13]. The extraordinary helplessness of the human infant at birth is not a design flaw. It is a trade-off: individual vulnerability was evolutionarily sustainable because our brain architecture promotes social structures of care. Evolutionary pressure was directed toward highly differentiated capacities for social engagement, attunement, and sharing of meaning. It is therefore plausible that impairment or distortion of these capacities in the dynamics underlying much of what psychiatry classifies as disorder [14,15,16].

3. The Symbolic-Theoretical Perspective: Cassirer’s Animal Symbolicum

As described above, biosemiotics shows how a frog, a rabbit, and a human being camping on a summer meadow all share the same Umgebung yet each inhabit a species-specific Umwelt. The human Umwelt, however—or, to use Husserl’s more precise term for the specifically human case, Lebenswelt (lifeworld) [17]—is of a fundamentally different character. This difference is generated by the human capacity for symbolic thought and by the embedding of symbols in cultural systems of meaning.

Ernst Cassirer (1874–1945), philosopher and colleague of von Uexküll at Hamburg, developed a comprehensive account of this symbolic dimension in his three-volume Philosophy of Symbolic Forms [4]. His central thesis is that human beings extend their lifeworld to an immeasurable degree through a network of symbols. Signs are functionally tied to specific biological responses. Symbols are different: they belong to the human world of social meaning creation, constituting a layer of reality that has no equivalent in the animal world.

This symbol network—comprising language, myth, religion, art, history, and science—does not represent a pre-given reality. It actively constitutes human reality. Cassirer therefore describes the human being not as animal rationale but as animal symbolicum: a creature whose mode of world-experience is irreducibly symbolic. To speak a language is not merely to use a communication tool. It is to inhabit a particular symbolic world, structured by metaphors, characteristic ways of framing causation and agency, narrative conventions, and evaluative categories.

Susanne Langer, one of Cassirer’s most important interpreters, distinguishes two fundamental symbolic modes. Discursive symbolism is linguistic, sequential, propositional, and analytic—the domain of science. Presentational symbolism is non-discursive, simultaneous, and holistic—the domain of music, visual art, and ritual. Presentational symbols can express contents that resist discursive language, especially feelings and states of experience [18]. This can be seen as an indication that for the important therapeutic task of bringing inner experience into adequate language, approaches that initially focus on presentational symbols may serve as a valuable complement or intermediate step. Humanistic Psychotherapy works at exactly this interface: in Rogers’ Person-Centered approach, Gendlin’s Focusing, Moreno’s Psychodrama, body psychotherapy, and approaches that integrate expressive arts therapy. With severely disturbed patients in particular, such approaches can first establish a shared mode of communication between therapist and patient. The ultimate goal, however, is for patients to engage as fully as possible with the micro- and macro-social processes of their society—processes that, in our culture, are to a large degree linguistic in character.

This raises an important question for psychopathology: what happens when the symbol systems that normally structure experience are disrupted or lost? Cassirer addressed this directly in his “Studies on the Pathology of Symbolic Consciousness” [4]. He drew on Finkelnburg’s [19] earlier concept of “asymbolie”. This concept describes the loss of the capacity for abstract symbolic use in aphasic patients. Such patients could not make the sign of the cross on request, could not correctly identify coins or banknotes, and could not treat the same physical object as a member of a general category. Cassirer and Goldstein—who integrated Cassirer’s approach in his influential work “The Organism” [20]—argued that what was lost in these patients was not an isolated cognitive ability. What was lost was access to the specifically human mode of world-constitution: the capacity to inhabit a symbolically structured lifeworld rather than a world of purely concrete, immediate, organism-specific meaning [21].

Norbert Andersch [22,23], a German-British psychiatrist and gestalt theorist who has argued for decades for a stronger theoretical grounding of psychopathology in Cassirer’s symbol pathology [4], emphasizes the tension between the self-centered intentionality of the individual organism and the socially constituted resonance-spaces that symbolic forms provide. Mental crises arise when this normal cultural achievement fails, wholly or in part. Individual symbolic forms may collapse. The capacity to switch between symbolic levels may be lost. The exchange between individual and environment becomes disturbed, and reality loses its meaning in part or entirely. Andersch [23] describes how people respond to such losses with tension-avoidance, complexity reduction, and regression to earlier patterns of meaning. These responses are often identified diagnostically as nothing more than deficit symptoms. Andersch, however, argues that these should be understood as protective attempts at self-regulation within the collapse of the symbolic matrix.

4. The Complementarity of Experiencing and Describing

The biosemiotic and the symbolic–cultural perspectives do not compete with each other. They are complementary with respect to two inseparably intertwined dimensions of human existence. To be human is to be simultaneously an organism with a biologically structured Umwelt and a cultural being embedded in a symbolically structured lifeworld. These two modes of world-engagement cannot be reduced to each other. Neither can be dispensed with [10,14,15].

In psychopathology and therapy, this complementarity can be articulated at three levels, each with distinct clinical implications.

At the first level—organism versus symbol—the human being is always already both. The world is experienced through the pre-reflective, evolutionarily pre-formed sign-systems of the biosemiotic Umwelt. At the same time, this experience is interpreted and narrativized through culturally inherited symbolic frameworks. Both modes operate largely outside conscious awareness [15]. To return to the summer meadow example: ants and frogs live exclusively within their respective Umwelten. The same is true, in one sense, for the human beings who join the animals on the meadow: A little girl delighting in the blue flowers, her father as a property developer eyeing the land for construction, her mother as a botanist seeking to identify the species precisely—none of them perceives “a summer meadow” as defined in an encyclopedia. Each perceives it largely as part of their own subjective lifeworld. And yet all of them also know, beyond their subjective experience, something of the more general meanings of “summer meadow” or “blue flower”. In the same way, the doctor and the patient meet in the shared surroundings (Umgebung) of a consultation room, each inhabiting their own lifeworld (Lebenswelt)—lifeworlds that differ considerably from the other, both at the organismic level and at the symbolic level of narratives, explanatory frameworks, and bodies of knowledge, although commonalities exist. Effective collaboration therefore requires both the creation of shared spaces of meaning and the development of ways of translating between these different lifeworlds.

At the second level—experiencing versus describing—the complementarity corresponds to the irreducible difference between the patient’s Befindlichkeit (subjective condition) and the clinician’s Befund (clinical finding). The point is not merely that subjective experience matters alongside objective findings. The stronger claim is that these are two genuinely different perspectives on the same reality. Each captures something the other misses. Both are required for clinical understanding. In brief: The “world” as it is described (objective/intersubjective aspects) and the “world” as it is experienced (subjective aspects) are two complementary perspectives. Both must be taken into account.

At the third level—organismic experience versus the patient’s narrative about that experience—the complementarity generates what is perhaps the most clinically distinctive insight of this framework. The patient’s lifeworld is not a transparent window onto their organismic experience. It is itself a symbolic construction. It is structured by culturally formed categories—narrative frameworks absorbed from significant others, or evaluative standards internalized from the social environment. When a patient says “I feel depressed”, the question arises whether they are adequately capturing their organismic processes, or whether they are applying a culturally available label to an experience that, on closer phenomenological examination, turns out to be something quite different. Perhaps it is a chronically unfulfilled longing, or a pervasive sense of inadequacy, or an unresolved grief. The diagnostic category, applied too quickly, forecloses precisely the therapeutic exploration that might help.

This also clarifies why the philosophical distinction between “first-person perspective” (subjective experience) and “third-person perspective” (external description and observation) is, from a clinical-therapeutic point of view, irrelevant because both perspectives are always intertwined. To understand myself in my most intimate inner experience, I must apply the cultural tools of language—the third-person perspective—to myself. Moreover, in ontogenetic development, this connection must be established through a “second-person perspective”: an empathically understanding attachment figure who appropriately symbolizes the child’s experience. This is precisely the socio-evolutionary task of caregivers—a task that is, on the one hand, fulfilled largely and automatically through evolutionarily pre-formed programs, and that, on the other hand, when insufficiently fulfilled, frequently promotes pathogenic development. In Humanistic Psychotherapy, the condition in which a person lacks adequate symbolic representations for understanding their own experience is called “incongruence” [24]. It describes a distressing relationship between a person and their own experience. This will be discussed again in the following section.

5. Therapeutic Consequences: Encounter, Symbolization, and Self-Organization

If psychopathology involves, to a significant degree, a disturbance in the symbolization of organismic experience, then the therapeutic relationship is not merely the vehicle through which techniques are delivered. It is the primary medium of therapeutic change. This is precisely what meta-analytic research on constructive psychotherapeutic change consistently indicates. Wampold and Imel [25] have shown that specific therapeutic techniques account for relatively modest proportions of outcome variance—effect sizes are typically below 0.20. So-called “contextual” or “common” factors account for substantially more: empathy (0.63), therapeutic alliance (0.57), goal consensus and collaboration (0.72), unconditional positive regard (0.56), congruence/authenticity (0.49). These are not incidental accompaniments of treatment. They are the core of what makes therapeutic change possible.

From the biosemiotic-symbolic perspective described here, this finding is not surprising. The therapeutic relationship is the site at which new symbolizations of previously inadequately symbolized organismic experience become possible. This is what the Humanistic Psychotherapy tradition has described, since Moreno [26], Buber [27], and Rogers [24], as “encounter” (Begegnung). It is not a technique. It is a quality of presence in which therapists neither maintain diagnostic distance nor identify with the patient. Instead, they bring themselves as persons while working with patients as subjects who have their own irreducible lifeworlds.

From a developmental perspective, this encounter recapitulates the primary process through which the capacity for symbolization is originally acquired. The infant’s organismic experience—affective states, needs, perceptions—becomes intelligible to the infant itself only through mediation by a genuinely responsive other. This other empathically receives these states and returns them, transformed into symbolic form, through gesture, voice, language, and narrative. Where this mediation is chronically inadequate—where the infant’s organismic experience is systematically misread, ignored, or overridden by the caregiver’s symbolic frameworks—parts of experience cannot be integrated into a coherent sense of self. The therapeutic encounter offers a second biographical opportunity for this primary developmental process. It is something called “re-socialization”: hitherto unsymbolized experience finds its way into symbolic form within the safety of genuine encounter. This concept of specific self-regulation processes is described in Humanistic Psychotherapy as “actualization” [24,28].

Without going into detail here, Person-Centered Systems Theory [14] provides a conceptual account of how this change occurs. Central to this account is the fostering of self-organizational processes, drawing on the interdisciplinary theory of non-linear dynamical systems and specifically on synergetics [29]. The four process levels distinguished within this framework—psychological and interpersonal processes, along with their embeddings in somatic and cultural processes—interact in ways that are essential for the stabilization or destabilization of key clinical processes at each of the other levels. Therapeutic change is not the result of external interventions that directly modify symptoms or behavior. It is the product of a change in the conditions under which the patient’s own self-organizing processes operate. Malignantly over-stable process patterns in a person’s psychic and interpersonal dynamics are modified by providing conditions for new patterns to emerge [14].

From the perspective of the complementarity emphasized in this article—between (somatic) experiencing and (symbolic) describing of “the world”—two further points deserve attention. First, psychological, interpersonal, and cultural–societal processes belong primarily to the domain of symbolic formations. Second, at the somatic level, Ciompi’s concept of “affect logic” [30] is relevant: because of the comparatively slow rate of change in biochemical parameters, affective processes form the framework within which the more rapidly changing cognitive processes—with their bioelectric basis—operate. This relationship between experiencing and insight, between somatic process and symbolic description, is of considerable importance for therapeutic understanding and practice.

When concepts of self-organization from systems theory are used to broaden diagnostic and practical perspectives, the complementarity emphasized in this article remains equally central. Systems theories typically distinguish between system and its environment—for example, the system of “doctor–patient interaction” within the environment of other “hospital processes”. But it is important to ask: which perspective on the doctor–patient interaction (or on hospital processes) is actually at stake? Is it the processes as objective observers would describe them, or the processes as the patient perceives them, or those as the doctor perceives them? Despite areas of overlap, it can hardly be assumed that these perspectives will yield identical descriptions.

6. A Plea for Extended Diagnostics

ICD and DSM codes undoubtedly fulfill important functions. By adopting one necessary perspective on human suffering—the observer’s perspective, classifying defined symptoms—they produce reliable descriptions and facilitate communication among clinicians and with healthcare administration. From this standpoint, they support epidemiological studies and a certain range of treatment planning.

Nevertheless, there has been extensive debate for decades, supported by both practitioner experience and research data, about the need to extend the diagnostic gaze to encompass a range of observable phenomena known to be relevant to clinical processes in psychiatry. Engel’s now widely recognized “bio-psycho-social” model represents an important step in this direction [2]. While Engel’s model focuses, with a clinical–epidemiological orientation, on psychological and social influencing factors, approaches within “semiotic cultural psychology”—such as those of Jaan Valsiner, Sergio Salvatore, and Gianluca A. Veltri—ask how human beings generate and culturally mediate meaning. More specifically directed toward the psychiatric context are the analyses of Renzo Carli and Rosa Maria Paniccia, who examine the social organization of meaning in interaction [31]. Important impulses for extended diagnostics also come from work on “4E Cognition” [32,33]—or the “4E Approach” [34]—which emphasizes that meaning is always generated as embodied, embedded, enactive, and extended, and that the human being is therefore to be understood holistically, with attention to body, environment, action, and context.

The focus chosen in this article—on the complementarity of bodily–biosemiotic and cultural–symbol–theoretical formative processes through which human beings meaningfully structure their relationship to the “world”—thus exists within a broad discursive field addressing related themes. The return to von Uexküll’s biosemiotics on the one hand, and to Cassirer’s symbol theory on the other, is not merely a historical tribute. Von Uexküll’s distinction between Umgebung and Umwelt is particularly sharp and provides a foundation for taking seriously the many pre-formed, evolutionarily acquired organismic structuring processes—processes that recent infant research has illuminated with surprising results. Cassirer’s symbol theory, and its extension by Langer, is especially well suited to situating the cultural–societal processes of meaning-creation in relation to their bodily–evolutionary complement. The actual entwinement of the logically distinct first- and third-person perspectives, mediated through the second-person perspective, is important for understanding both pathological and therapeutic processes. And the question of what we can and want to speak about in diagnostics at all—whether it is the categories of observers, the experiences of subjects, or their (often inadequate) descriptions—can only be addressed by recourse to these different perspectives and processes.

For discourses on the etiological foundations of psychopathology, Cassirer’s work on symbol pathology—briefly outlined in the preceding sections—is also relevant. This is an approach developed and elaborated today especially by Norbert Andersch [22,23].

When one is willing to grant meaning-generating processes their appropriate place, a research-logical problem arises with respect to standard diagnostics. ICD/DSM diagnostics, manualized interventions, and Randomized Controlled Trial (RCT) design form a closed, self-reinforcing system. That is a strength—but it also reveals the system’s limits. If one takes seriously the view that human beings interpret situations and respond to their meaning rather than to their objective configuration, then the so-called “independent variable” (the intervention) becomes de facto dependent on the patient’s interpretation. The experimental schema—which defines interventions as the independent variable acting on the dependent variable of illness course—breaks down. In the extreme case, pure RCT research produces not robust results but artifacts.

Overall, there are thus good reasons to extend standard diagnostics. This article argues that within the already diverse range of approaches to such extension, the complementarity of human existence in the world—as laid out in von Uexküll’s biosemiotics and Cassirer’s symbol theory nearly a century ago—deserves to be considered an important perspective.