An ontology of difference: Speculations on psychotherapy,mental health work,difference,and ethical realism

Abstract

In mental health and substance use, assessment and the resulting diagnosis determine the choice of treatment or therapy to be used with the individual client. In health policy today, treatment should be evidence based and standardized. Health care thus draws on New Public Management principles, where only those methods and practices considered to be evidence based are accepted in the “market” of public health care. However, we view psychotherapy and mental health work as a meeting between persons that in the spirit of standardization might well be labelled “an individual case.” Psychiatric diagnoses are subject not only to standardization but also to a focus on identity and similarities, as more generally seen in Western science and philosophy. Difference arises when comparing identities; difference is secondary to identities. In this article, we draw on the philosophy of Deleuze and Guattari to explore whether an ontology of difference could be helpful in therapy. An ontology of difference speaks to our experience as therapists, researchers, and teachers that there will always be difference, and that identities are secondary to difference. Rather than providing standardized answers, knowledge is useful for speculating, experimenting, and bringing forth innovative suggestions as to what could be helpful therapy in the individual case. We do not know what psychotherapy and mental health work can become and we need tools for experimentation, suggestions, and visions of what could be helpful. This must be based on collaborative relationships with those who seek help and support. The central question is, then: What can therapy become?

The paper ‘Return to reality: What does the world ask of us?’ (Bøe et al., 2024), raised questions about the relationship between the dominant epistemological focus in psychotherapy and mental health work on the one hand, and reality on the other. In the present paper, we speculate around the practice of psychotherapy and mental health work as it takes place in actual health care contexts from a non-dualistic and non-representational ontological stance. We argue that the dominant focus in psychology is based on an ontology of identity with resulting generalizations built on research using randomized controlled trials placed at the top of an evidence hierarchy. Here, “evidence” simply means that which is found in randomized controlled trials and meta-analyses of such research. Our concern is that this focus with its resulting production of research findings, theories, and knowledge about psychotherapy and mental health work could come between us therapists and our clients, and their reality. This concern has made us think that maybe, in the actual practice of psychotherapy and mental health work, we need to move away from practices that have their main focus on epistemology, knowledge, interpretation, and meaning, and bring ontological work and ethical practices to the centre of our concern. This means to speculate on the composition of the real, not allowing knowledge and evidence of the real become the predominant view.

Bøe (2021) made a distinction between ethics as a systematic investigation of values and norms that guide practice and ethical as an ethical realism that involves the obligation to do good. Ethical realism can be stated in the following manner:

(T)he idea that ethics is not something we add to our lives or that we construct through social-cultural reflections and interpretations. Ethics, in the sense of a call or obligation to do good, is an existing imperative inherent when we face reality and other human beings, prior to constructions and interpretations of reality and of other human beings . . . (Bøe, 2021, pp. 221–222)

For us this means that ultimately it is what we do and what happens in actual events of practice that decide whether these acts and doings are ethical. This brings us right into the actual therapeutic situation and event with the question: What would be “good,” helpful, and important for the other(s) that we encounter in psychotherapy and mental health work? The answer to ethical questions is always found in the actual practice and event of therapy, not in the form of predetermined principles and procedures as responses to the demand made by predefined values and norms of what is good.

However, ethical realism is certainly not only directed at the good, whatever that means for the person(s) in therapy. It concerns equally the ways to avoid doing what is bad for the person(s) and the adversities in their life situation or prior history. It is about trauma, but just as much about those small things that pile up and end up hurting more than the person can deal with. It is about oppression, marginalization, microaggressions, and simply the fact that life and living are not a straightforward successful journey. It is full of small and big things and events that challenge us, bring us down, and which we have to relate to in order to go on living as best we can, given our circumstances. What these events and situations are for the person we meet is not given beforehand. Research findings, theories, and prior experience do not give final answers to what we need to deal with in therapy. We need to strengthen our attentiveness towards what others present to us and their circumstances.

Therefore, the move from epistemology to ethical realism clearly privileges practice, i.e., what takes place in the actual events of the individual therapeutic encounters and dialogues. Here, generalized knowledge, in the form of group-based research findings and theoretical formulations and interpretations of such research and experience from previous therapies, is made into a reservoir of suggestions for how to do therapy, always negotiated and realized in a therapeutic event. However, the prioritization of ethics and what is good and helpful is addressed in these events and what they lead to in the becoming of the person’s life and living (Andersen, 2021).

One way of viewing this is that therapists and clients together are regaining control over the therapeutic situation, relegating knowledge to the status of tools for helping and supporting the participants in therapy. At the same time, an ethical approach also liberates generalized knowledge from the responsibility of giving reliable and correct answers to questions of what is good, proper, and right in mental health practice. Instead, knowledge, in the form of research findings, theories, philosophies, and other systems and formulations of how to do therapy, can be set free to be speculative, innovative, and experimental, especially in situations where pre-prepared, theory-specific, and evidence-based practices are not helpful. An ethical approach critically examines the knowledge from randomized controlled trials based on theory-specific methods that reveal that one part of the experimental group is helped, another part is unchanged, while yet another part has actually become worse during psychotherapy (Lambert, 2010). The no-change group and the group that deteriorates need something else. Here, knowledge is useful for speculating, experimenting, and bringing forth innovative answers to what could be helpful therapy in the individual case. Stated differently: We do not know what psychotherapy and mental health work can become and we need tools to find this out through experimentation, suggestions, and imaginings of what could be helpful. Further, processes of experimentation and speculation must take place in a collaborative relationship with those who come to us for help and therapy. This brings us back to knowledge as a reservoir of suggestions for possible practice. It also raises the question of whether there are formulations that could help us in our quest for an ethical practice in the individual case and that support the above thoughts on the relationship between practice, research, and knowledge. At this point, we wish to explore whether an ontology of difference could be helpful, i.e., an ontology that suggests to us how our actions in the real can bring forth new helpful practices in “an individual case of therapy.” The important question is: What can therapy become?

We see the doing of psychotherapy and mental health work as a meeting between persons that in the spirit of generalization can easily be called “an individual case” among “other individual cases.” By emphasizing an ethical realism and the actual meeting and event of therapy, we let our descriptions and concepts point outside themselves to a reality that always overflows these descriptions and concepts. This leads to the question of how to see the person in a way that allows the person to show us something that always exceeds the descriptions we can make of that person. The paradoxical situation we place ourselves in here is that we want to develop concepts, descriptions, and perspectives that can make suggestions and help us in relating to individuals while also allowing and making space for overflow beyond the linguistic expressions we use about the specific person we meet. For this, we seek help in an ontology of difference.

An ontology of difference

The following presentation and perspectives are inspired by the work of French philosopher Gilles Deleuze and French psychoanalyst Felix Guattari. None of the authors of this paper are academically trained philosophers. We are simply readers of philosophy who have found that this reading inspires us to think about our practice in new ways. We will try to capture and put to work some of the concepts we find in the work of Deleuze and Guattari, though without pretending to have a full overview of their philosophical oeuvre. This means that the focus is not on a “correct” presentation and understanding of the ideas of the authors who inspire us. We find some comfort in the following:

There are (. . .) two ways of reading a book: you either see it as a box with something inside and start looking for what it signifies (. . .) And you treat the next book like a box contained in the first or containing it. And you annotate and interpret and question, and write a book about the book, and so on and on. Or there’s the other way: you see the book as a little non-signifying machine, and the only question is “Does it work, and how does it work?” How does it work for you? If it doesn’t work, if nothing comes through, you try another book. This second way of reading’s intensive: something comes through or it doesn’t. There’s nothing to explain, nothing to understand, nothing to interpret. It’s like plugging into an electric circuit. (Deleuze, 1995, pp. 7–8)

Nothing to explain, nothing to understand, nothing to interpret might be exaggerating, but, in line with our ethical approach, we have treated the writings of Deleuze and Guattari in line with the second description of reading.

The focus is on the thoughts and perspectives that the reading of their work elicits in us concerning our practice as therapists, teachers, and supervisors in the fields of psychotherapy, mental health work, and addiction (Bertelsen et al., 2025). Or, in the words of Deleuze (1995), “. . . in contact with what’s outside the book, as a flow meeting other flows, one machine among others, as a series of experiments for each reader in the midst of events that have nothing to do with books . . .” (p. 9).

Etymologically, “to be inspired” means “to be breathed into (life)” (Partridge, 1966, p. 652). Inspiration is about our vitality, our ability to move, express, and act (Stern, 2010). When we say that we are inspired by authors and researchers, we mean that they help us to move forward in our thinking, to give us ideas on how to act, suggesting ways to express our thoughts and experiences, while also invigorating us in our work. Although we have been inspired, a book is only “. . . a little cog in much more complicated external machinery” (Deleuze, 1995, p. 8). This becomes especially important in situations where we are stuck (McLeod & Sundet, 2020), where we do not know what to do but still have to act. To be inspired does not mean to be given clear answers and instructions on what to do. Inspirations are starting points for thinking, experimentation, and trying out new ways of responding in collaboration with our partners in therapy. This paper is not a presentation of the philosophy of Deleuze and Guattari, but a presentation of what our reading of these authors has elicited in us in relation to our practice. One such powerful idea is the ontology of difference.

In explicating different kinds of empiricism, with special attention to the transcendental empiricism of Gilles Deleuze (Deleuze, 1990, 1994), St. Pierre (2016) warns against the “rush to application” (p. 121). She adds that this is particularly relevant to applying the concepts of Deleuze and his work co-authored with Guattari. The transcendental empiricism of Deleuze “. . . is not an epistemological project – it is not even an empiricism in the traditional sense – and it cannot be used in conventional social science research methodologies” (St. Pierre, 2016, p. 121). With regard to the philosophy of Deleuze and his works with Guattari (Deleuze & Guattari, 1987/2013), her advice is to “read and read again until its concepts overtake us and help us (. . .) to what we have not yet been able to think and live” (St. Pierre, 2016, p. 122). We take this as advice to slow down and not jump to the application of these ideas and concepts before we know their meaning or even understand them. Here, the words of Alexander Pope (1995) come to mind: “Fools rush in where angels fear to tread” (p. 82). Now the present authors are no angels. As practitioners, we are more like fools that rush in and apply any concept or idea as soon as it evokes ideas on how to act, especially in situations of being stuck and not knowing what to do (McLeod & Sundet, 2020). For us, this is due to our experience as therapists that in the present moment and event of therapy, we cannot put the book aside and come back to a new reading later, as we can as academics. We need to act, to respond in the present moment in our relationship with people and families we encounter in the field of mental health and substance (ab)use.

Our reading of Deleuze and Guattari (1994) has shown us that they do not primarily invite us to understand, but to let their concepts evoke ideas for practice and new manners of being together and living. We take this as invitations to experiment, to create ways of thinking, ways of finding or creating concepts that invite us to act differently, especially in situations of “stuckness” or when we simply encounter something we have not previously experienced. This is where we have found that Deleuze’s (1994) concept of difference invites us to think new thoughts and perform new practices in psychotherapy and mental health work.

Difference and difference in itself

From Deleuze’s (1994) discussion and explication of the traditional and dogmatic image of thought about difference, we will address three approaches to difference. These three approaches should not be understood as on a continuum. The third is developed by Deleuze as a way to critique the other two. The first two are grounded in traditional Western thinking from science and philosophy. The first one is a focus on identity and similarities. Examining similarities across individual entities, persons, objects, events, and situations establishes generalities or identities based on similarities between the individual units in question. They are not completely identical, but are similar enough to be given the same name or membership in a class or group. Psychiatric diagnoses are one example of this. If enough elements or symptoms are found in connection with a person, this person becomes a member of the group “depressed” or “having a depression.” Having established this, we could then explore different kinds of standard treatment, and see which are most helpful for persons belonging to the group of depression. The randomized controlled trial is the preferred method to establish this. Statistical patterns or frequencies at the group level decide what works for the individual. Difference arises here as something emerging from a comparison between identities, such as between two methods applied to the same diagnosis. Difference is therefore secondary to identities.

The second approach to difference involves dialectics. One argument, a thesis, in opposition to another argument, the anti-thesis, merges into a new argument, the synthesis. Here again, there are two different arguments or two identities that give rise to a third argument or identity. Again, difference is an effect of bringing together the thesis and anti-thesis as two identities in opposition, where a new identity emerges out of this opposition. Both the bringing together of the thesis and anti-thesis and the resultant synthesis demonstrate that difference is secondary and identity is primary. The main epistemological focus is thus descriptions of identities and generalities. The task of difference is simply to indicate the distinctness and differentiality of the generalities. In a randomized controlled trial, the different effects of two theory-specific therapies are investigated and if a difference is found, the therapy that is shown to be the best or to have the most effect at the group level is seen as a recommendation for how one should generally treat e.g., a person diagnosed with depression. The problem is that people who do not follow the identified pattern are statistically equalized. The following statement gives the reason why this supposedly is not a problem: “There are variations between humans, but there also is a relatively uniform human nature. This means that investigations that work on large groups of humans will probably work for random individuals” (Kennair et al., 2002, p. 9). The assertion is that if we know something about what is helpful for the many on the group level of an investigation, we will know what will be helpful for the individual. One has to move beyond the particular, beyond personal stories, and consider what demonstrates efficacy at the group level, and let that govern our practice (Kennair et al., 2002). This is the central idea of the evidence paradigm of psychotherapy. In this view, the individual person becomes a generalized category split off from the person’s context and unique experiences and life practices. These become noise under the domination of the identified statistical pattern to which the person belongs. Once more, we find inspiration in Deleuze (1994):

. . . difference becomes an object of representation always in relation to a conceived identity (. . .) an imagined opposition or a perceived similitude [emphasis in original] (. . .) For this reason, the world of representation is characterized by its inability to conceive of difference in itself . . . (p. 182)

The third account of difference opens up an avenue for the individual as contextualized and subjectified. This is what Deleuze names difference in itself (Deleuze, 1994), clearly distinct from the first two forms. Difference in itself marks an ontology, an ontology of difference. Todd May writes about Deleuze: “The term ‘difference’ is not another concept designed to capture the nature of being or the essence of what there is. It is a term he uses to refer to that which eludes such capture” (May, 2005, p. 82). The relationship between difference and identity is turned on its head. In the first two forms of difference, difference is secondary to identity. It arises through comparison. With difference in itself, difference is primary, and identity arises from it. Difference makes a difference in that first there is difference and then identity arises through the difference it makes (Bateson, 1973). The first two accounts of difference are about the practicalities of comparison and similarities. The third is about ontology, about the “nature” of the real.

In the field of mental health and substance (ab)use, we have all met people and families who in their response to their previous therapy have eluded the conceptualizations and practices to which they were exposed. Further, when meeting these families, we soon experienced the limitations of our own practices. Our experiences of the event of therapy are that this leads to more of a groping in the dark than targeted explorations, and often to stumbling upon some haphazard idea and practice never used before, rather than consciously invented practices:

When two divergent stories unfold simultaneously, it is impossible to privilege one over the other: it is a case in which everything is equal, but “everything is equal” is said of difference, and is said only of the difference between the two. However small the internal difference between the two series, the one story does not reproduce the other, one does not serve as a model for the other (. . .) the sole origin is difference, and it causes the differents which it relates to other differents to coexist independently of any resemblance. (Deleuze, 1994, p. 159)

There is always difference. Identity and similarities are effects of difference and not the other way around. Therapeutically, then, what brings us further is by attending to difference. For instance, one family asked the team that one of us (RS) worked in to help them become a tighter and closer family. Nothing the team introduced seemed to lead towards this state. The breakthrough came when one of the children answered that she thought that cooking together could bring the family closer. The therapist responded with some surprise: “What did you say?” The child answered: “It happens when we cook lamb.” Here, difference does not arise through a comparison between two familiar and different therapeutic interventions or because of a dialectical thought process between different interventions. It simply arises as a difference in itself. It is felt in the body as the intensity of surprise or questioning without words or in search of words. The question can then be: Can this be included in what we do? Difference in itself becomes something that elicits thoughts that are new to the therapist, “something” without content that had eluded the therapists and which must be given content and identity from the point when it appears and differentiates itself, experienced by the therapists as a difference that is about to make a difference (Bateson, 1973). Overtaken by the difference in itself, it makes a difference in that ideas for practices spontaneously arise in the dialogue between the family and the therapist on the details of a meal with lamb. The next step was to make and participate in the meal. In the end, the family stated that this meal was an important event in building closeness in the family.

As a foolish rush into the application of philosophical ideas, the above example touches upon the experience of being a therapist who confronts the feeling of not knowing what to do or how to go on but who still goes on by stopping at something that is different in itself for the therapist. Based on this difference, one starts to think about possibilities of what one can do, and, in the doing, one finds that something new or sought after arises: here, a closer family. By doing, the family is undergoing a process that brings them closer (Bertelsen et al., 2025). The context is that of a family and their therapist that do not know how to go on and in this situation; a child’s spontaneous utterance about a meal becomes a new and unique path of action. The girl presents herself as a difference in itself, through her contribution to the conversation in the context of not knowing what to do. Although we can always find similarities between people, ultimately no two people are fully alike. As May (2005) puts it:

Here is a way of seeing the world: it is composed not of identities that form and reform themselves, but of swarms of difference that actualize themselves into specific forms of identity. Those swarms are not outside the world; they are not transcendent creators. They are of the world, as material as the identities formed from them. And they continue to exist even within the identities they form, not as identities but as difference. From their place within identities, these swarms of difference assure that the future will be open to novelty, to new identities and new relationships among them. (p. 114)

Again, we see that there is always difference and that each of us is intrinsically different from others. For the therapist, difference in itself, that which is prior to any identity and content, becomes an opportunity for new practices that fit the context and predicament of the participants.

Multiplicity tolerates no dependence on the identical in the subject or object. The events (. . .) of the Idea do not allow any positing of an essence as “what the thing is”. No doubt, if one insists, the word “essence” might be preserved, but only on condition of saying that the essence is precisely the accident, the event, the sense . . . (Deleuze, 1994, p. 251)

Seeing “essence” as “the accident, the event, the sense” has implications for how we view treatment, especially when methods that help those who fit in with generalized and standardized descriptions of therapy do not help those in front of us. This brings us to the dominant concepts of knowledge-based and evidence-based practices. Based on the above, the argument is that this dominant view must be challenged. In the following, we will introduce perspectives found within diverse fields of psychology and philosophy that support this argument. To do this we first need to return to our reading of Deleuze and Guattari (2013). The two first authors have had a project of reading A Thousand Plateaus. The reading has given them a series of challenges and strange experiences. One particularly important experience concerns the question of being critical. Within the dogmatic image of thought, with its reliance on difference as secondary to identity, negations have a tendency to arise (Deleuze, 1994). In A Thousand Plateaus we have encountered a number of pairs of concepts that at first glance appear as dichotomies. Examples are the major and the minor, stasis and change, extensive and intensive, and arborescent and rhizomatic. One such pair of concepts, royal and nomadic science, has been of particular relevance for the practice of psychotherapy and mental health work. Royal science points to the evidence paradigm of modern psychotherapy and mental health work. Nomadic science, as we will argue, indicates another way of thinking about and doing therapy and research, which opens up where we find that royal science tends to close down and exclude. Nomadic science, in the words of John Shotter, is “. . . for people who have to think in the movement, ‘on the run’, both from within the midst of complexity and from within a unique never-before-encountered concrete circumstance” (Shotter, 2011, p. 37).

When reading A Thousand Plateaus, it is easy to experience in each plateau a text that seduces the reader to end up accepting one concept as dominating the other, as in a dichotomy. Years of training within the dogmatic image of thought reinforce this in us, yet at the end of reading the plateau we are thrown out of this bliss of either-or, negations and contradictions, into the complexities of saying “yes” to affirm what we are critical of. There are always differences to be affirmed. In this paper, we have a critical view of the evidence paradigm with its dominance of randomized controlled trials and the resulting generalizations. At the same time, we are again and again forced to realize that difference is not opposition and contradictions within an ontology of difference. It is differentiations into situations and events of multiplicity where a research strategy such as the randomized controlled trial is both “of the good” and “of the bad,” and so is evidence-based knowledge. Many are helped by therapy methods that are evidence based. Our concern is the other side of the coin. Randomized controlled trials also show us that a part of the patient group under study is not helped (Sundet, 2021). Our experience is that this group of patients, in our health care system, is easily forgotten or excluded through explanations that they are the problem, due to e.g., a lack of motivation, of cognitive capacities, or of the ability to mentalize, to mention a few externalizing manners of excluding patients from therapy. This is where an ontology of difference is of help. All differences, all patients, must be related to and included in psychotherapeutic and mental health practices. This means exposing mental health workers to uncertainty and situations of not knowing what to do. If in the following we appear too much as either-or, it is important to underline that in the end what we are critical of must be affirmed as part of the diversity that we meet in our practice with its possibilities for creating both problems and opportunities for patients and therapists. Based on the above, the paper will adopt a critical attitude towards the royal science of the evidence paradigm, while also affirming it as part of the multiplicity of science and practice. In the following, we will introduce perspectives found within diverse fields of psychology and philosophy that support this critical view.

Psychology

The Norwegian psychologist Jan Smedslund points out three sources of knowledge for practitioners. The first is what we know as humans because we are humans, the second is the knowledge we have as participants in a culture and language, and the third is knowledge about specific unique people with their life circumstances and prior experiences (Smedslund, 2012; Smedslund & Ross, 2014). What we have in common enables us to enter into relationships and communication, although the uniqueness of the individual will always colour and make a difference in this interplay. Thinking with Deleuze (1994) on difference and repetition, we can never be certain in our relationship and communication with the other; novelty as difference in itself is always there because repetition, the return of what we have in common, always returns with difference. Things may seem identical or repeated, yet:

The subject of the eternal return is not the same but the different, not the similar but the dissimilar, not the one but the many, not necessity but chance. Moreover, repetition in the eternal return implies the destruction of all forms which hinder its operation, all the categories of representation incarnated in the primacy of the Same, the One, the Identical and the Like. (Deleuze, 1994, p. 160)

Here, we leave the safe haven of theories and research findings, seeing such entities as pointers and suggestions for possible practices, for paths of experimentation and new forms of practice that can become paths or lines of flight (Deleuze & Guattari, 1987/2013), and enter into something new and hopefully better for those we encounter, but certainly without guarantees (Deleuze & Guattari, 1987/2013). In the memory of the prior history of eating lamb, this eating, as repetition as difference, enabled the family to have a new experience of themselves as a family:

Repetition in the eternal return excludes both the becoming-equal or the becoming-similar in the concept, and being conditioned by lack of such a becoming. It concerns instead excessive systems which link the different with the different, the multiple with the multiple, the fortuitous with the fortuitous, in a complex of affirmations always coextensive with the questions posed and the decisions taken. (Deleuze, 1994, p. 147)

From the perspective of a therapist who applies such a view of difference and repetition, a double predicament emerges: “I know and I don’t know,” or as Deleuze (1994) puts it:

We never know in advance how someone will learn (. . .) There is no more a method for learning than there is a method for finding treasures, but a violent training, a culture of paideïa which affects the entire individual (. . .) Learning is only the intermediary between non-knowledge and knowledge, the living passage from one to the other. We may well say that learning is, after all, an infinite task . . . (p. 215)

For therapists there is no peace. There will always be a question of learning to relate to when participating in the new and different. It is about “. . . the whole uninterrupted realm of ceaselessly flowing, spontaneously occurring, always interplaying, activities – both material activities as well as those of a psychosocial and sociocultural kind . . .” (Shotter, 2011, p. 9). What is common here is a starting point where therapists will always have to check and be ready for common aspects to reappear in different ways, or something radically new to emerge. This thinking with Deleuze leads us to think that difference in itself, that which is no longer the same or is something not met before, speaks to the differentiality of the individual. The position taken here is to allow oneself to think that difference in itself is experienced as unique, particular, and foreign. This uniqueness and foreignness must be given content in the actual dialogical and collaborative interplay of therapy. This has implications not only for practice in mental health and substance (ab)use work but also for research and the way we view knowledge of the individual. In developmental psychology, this manifests itself as a protest against the dominant perspective of creating generalized descriptions and explanations of development.

Developmental psychology

Classical developmental psychology represents a field of theorizing, research, and knowledge where a generalized entity, such as the growing child, is established (Stern, 1998). By studying vast numbers of children differentiated into age groups, and measured on a series of abilities, i.e., physical, cognitive, emotional, and social “parameters,” developmental standards or expectations of developmental trajectories are established. The hope is that such standards or expected developmental trajectories can help parents, schoolteachers, and practitioners to judge whether a child is within the limits of normality or in the range of deviance and pathology. This is not far from forms and essences in classic Greek philosophy, where not fitting the template is considered deviation per se (Deleuze, 1994). In an ideal world, this would enable us to let those within normality maintain their good development, while we care for those who deviate and show pathology through treatment and educational methods shown to be efficacious for the deviance and pathology in question.

An example of this is attachment theory, developed by Bowlby (1997) and operationalized for research by Ainsworth. Through the “strange situation,” an experimental situation, children are classified as having secure attachment, ambivalent-insecure attachment, or avoidant-insecure attachment (Ainsworth et al., 2015). A fourth attachment style has been added: disorganized-insecure attachment (Main & Solomon, 1986). When a child is categorized correctly in this scheme, a series of issues can be investigated by correlating the child’s attachment style with whatever one wants to know. One of the most fundamental issues for the practitioner is: Is there a relationship between the different attachment styles and psychopathology? A corollary here concerns parenting styles and ways of caring and the development of the different attachment styles. A causal chain or sequence is established. Parenting and caring can lead to insecure attachment styles that give rise to psychopathology. However, this simplified description does not do justice to the actual research (S. White et al., 2020). The problem is that findings from research in journals are turned into simplified handbook versions (Fleck, 1979; S. White et al., 2020).

An example of this is Circle of Security Parenting (Cooper et al., 2005), a parental guidance programme. On the one hand, its simplified metaphors and pragmatic explanations can be very helpful for parents who ask for guidance on how to improve their interplay with their child. On the other hand, the simplicity and pragmatics easily obscure the developmental diversity that the research describes. This is especially risky with regard to diagnosing pathology and evaluating parental caring practices. What Deleuze and Guattari (1987/2013) describe as “the molar” involves something:

. . . solid that we can rely on. Molar lines have truths, universals, order. If we’re surrounded by a sea of chaos, why wouldn’t we cling to the first solid thing to come along? (. . .) Fear keeps us attached to our molar lines, and sometimes rightly so. (Adkins, 2015, p. 137)

Fortunately, developments in the field of developmental psychology itself have led to warnings of the dangers of overgeneralizing a child and of overlooking developmental uniqueness and idiosyncrasies that could represent adaptive abilities just as well as pathology. From the field of developmental systems theories (Cantor et al., 2019), there are strong arguments for a shift from a generalized view of development and children to a view of the development of the individual unique child. The argument is that “. . . individual variability . . . is pervasive at every level of analysis, from minds (. . .), to brains (. . .), to genomes (. . .), and cells (. . .). In each case, individual variability is the rule, not the exception” (Rose et al., 2013, p. 132). Preparing a meal is rarely an “answer” suggested in a psychology textbook, and there are several good reasons why. Responses or answers when things seem to be stuck are often found outside manuals and guidelines. As a comment on traditional sciences and their “root-books,” Deleuze and Guattari (1987/2013) write:

We’re tired of trees. We should stop believing in trees, roots, and radicles. They’ve made us suffer too much. All of arborescent culture is founded on them, from biology to linguistics. Nothing is beautiful and loving or political aside from underground stems and aerial roots, adventitious growths and rhizomes (. . .) Thought is not arborescent, and the brain is not a rooted or ramified matter. (p. 15)

The consequence for mental health and substance (ab)use practice is that the generalized descriptions of development are, at best, a starting point. They must always be checked against the uniqueness of the child and the family that shows itself in the therapeutic interplay or assessment situation. Here, “. . . for certain, the average is not good enough if the goal is to understand individuals. We must explain patterns of individual variability” (Rose et al., 2013, p. 132). From a research and empirical point of view, this brings the individual out of the shadows of the general. To further expand our thinking on the individual and individuality, we will now turn to another thinker from philosophy.

Plurality, natality, and the other as difference in itself

A famous statement by philosopher Hannah Arendt (1958/1998) reads: “Plurality is the condition of human action because we are all the same, that is, human, in such a way that nobody is ever the same as anyone else who ever lived, lives or will live” (p. 8). Drawing on Arendt, let us think that the child entering the world presents something that has never been in the world before. In this way, the child becomes an example of what we have named as difference in itself. We do not know what we will meet when we meet the newborn child. We can have guesses and expectations based on our general view of humans and their development. It is a child like any other child but unique. A second concept from Arendt (1958/1998), natality, “the birth of new men and the new beginning” (p. 247), speaks to this uniqueness and individuality. New means never previously experienced nor yet caught in descriptions, nor given content or identity. This invites a relationship where generalities, described identities, and membership in classifications are secondary to this uniqueness and individuality, here conceptualized as difference in itself. New beginnings are not merely a literal description of the birth of a child. In any interplay and relationship, novelty arises. In thinking with Deleuze (1994), that which is repeated is always with a difference. There will always be something undescribed in any description. Furthermore, Deleuze offers an alternative to modernity’s notion of the ego or the self, and the idea that one goal in therapy is to unravel what lies behind a symptom or a certain (often deemed undesirable) behaviour. He argues that there is nothing behind the mask but further masks, and that even the “. . . most hidden is still a hiding place, and so on to infinity. The only illusion is that of unmasking something or someone” (Deleuze, 1994, p. 136). He continues: “The ego is a mask for other masks, a disguise under other disguises. Indistinguishable from its own clowns, it walks with a limp on one green and one red leg” (Deleuze, 1994, p. 141). What to make of this? Are people like onions, where we peel one layer after another, only to discover there is nothing there? No! Drawing on Deleuze’s philosophy, Roberts (2006) presents a way of understanding subjectivity. It is too comprehensive to present in detail here, but time is of the essence. The subject does not withstand despite time passing but is rather constituted by it. What Deleuze denotes the passive synthesis of time makes experiences of continuity possible. This is no conscious act, and Roberts also points out that perceiving oneself from the outside is impossible, glimpsing who one is or once was. Now is the only thing that exists. We are constantly changing, and are never who we used to be, being influenced by the past, with prospects for the future. Further, “. . . although I do not consider myself to be the same person as I was 20, 10 or even 2 years ago, I also have the sense that those seemingly ‘distinct selves’ were, in some way, ‘still me’” (Roberts, 2006, p. 198). This way of perceiving the self and subjectivity, Roberts argues, contrasts with modern ways. What may be perceived as modernity’s self is often considered rational, unified, and stable. Hence, “. . . any perceived ‘deviation’ from this characteristically ‘modern self’ is seen as a possible ‘sign’ of ‘mental illness’. . .” (Roberts, 2006, p. 191). As practitioners and therapists, one way of reacting could be to facilitate “. . . ‘movement back’, or ‘re-instatement’ of, the ‘modern self’ . . .” through treatment or cure (Roberts, 2006, p. 202). Inspired by Deleuze, Roberts (2006) argues that the subject or the self should not be perceived as some innate, stable entity located within the individual. Rather, Deleuze’s work “. . . suggests to contemporary mental health care that, rather than being ‘stable’ or ‘fixed’, subjectivity should be understood as ‘dynamic’ and in a continual state of ‘evolution’” (Roberts, 2006, p. 199).

In the world of therapy, narrative practitioner Michael White has underlined that life is always richer than our descriptions of it. Whatever our experience and descriptions of a person’s actions, there will be unique outcomes (M. White, 2007), differences in themselves, that indicate the possibility of new and richer descriptions of the identity and actions of the person. The point is that novelty, difference in itself in a relationship, is what we need to attend to in any therapeutic endeavour. Uncertainty and a possible abyss of not knowing is therefore a reality that we must expect when working in the field of mental health and substance (ab)use. In this uncertainty, we also find ethics.

Ethical psychotherapy and mental health work

It might be inappropriate to include Levinas in a paper that finds its main inspirational source in the work of Deleuze and Guattari. There are clear tensions and differences between these authors, such as in the question of universality (Adkins, 2015; Smith, 2012). Despite this, we find some of Levinas’ distinctions helpful in directing our attention to important aspects of ethical psychotherapy and mental health work. Two citations from Levinas (2006) connect to the thoughts of this article. Firstly, in meeting another person, “. . . there is absolute foreignness of an unassumable alterity . . .” (p. 148). Secondly, in Western philosophy, there is “. . . a reduction of the other to the same . . . to receive nothing of the Other but what is in me . . .” (Levinas, 1991, p. 43). From the position of this paper, the foreignness in the first citation refers, for us, to the experience of uniqueness and difference in itself. Meeting another person always brings us into the uncertainty that a foreigner installs in us. Can we communicate? Can I understand or at least develop a relationship with the other that gives me an experience of some kind of common feeling and companionship?

The warning in the second citation is that whatever we do we must not reduce the other to our perspective and our experience of the world and living. We are confronted with the radical difference of the other in that we cannot take any description or explanation of the other for granted. This means that there is a gap between the knowledge produced by the science of the general, exemplified in the field of psychotherapy by evidence-based, theory-specific therapies, and what happens in actual therapy sessions. It does not mean that evidence-based methods are not to be used, only that with any sign of no change or a detrimental development the uniqueness of the other must be attended to. At the same time, it is the response of the other to our response that is decisive. Therapy is about becoming together. It needs to be dialogical and collaborative (Shotter, 2011). In practice, feedback from the people we encounter is a decisive part of the therapy (Duncan & Miller, 2000; Sundet, 2012, 2014).

This is where we find a source of ethical psychotherapy and mental health work. We cannot escape the Other. On the one hand, Deleuze and Guattari’s (1987/2013) philosophy and Bateson’s (1973) view of family therapy argue for a concept of the individual that does not stop at the skin. The individual is extended and relational, part of the assemblage and system in which it is inherent, always constituted and defined by what it is part of (Roberts, 2006). On the other hand, as therapists we meet, relate to, and participate with individual people in their unique first-person experience (Lingis, 2007). The two citations from Levinas help us remember that each of us is unique with idiosyncratic first-person experiences. For each of us there is a foreignness, a difference in itself, when we encounter the individuality of the other. Ethical psychotherapy and mental health work must respect the relationality and embeddedness on the one hand, and the uniqueness and foreignness of the other on the other hand. This means that severing the ties between the individual person and her or his context and relationships leads to a loss of individuality and uniqueness. The person becomes a generalization, being no longer an individual but an example of a generalized and de-contextualized concept, expressed through findings of randomized controlled trials, and showing itself in practice as a privileging of standardization (Sundet, 2021). This brings us to science, research, and practice.

Science, research, and practice

The contemporary solution for almost all types of problems and challenges is knowledge or evidence, the product of science and research. The authors subscribe to and support the perspective that knowledge is central and decisive in problem solving and in meeting the challenges of life in a productive and effective manner in our contemporary society. So, for us, it is not about rejecting royal science; it is about including nomadic science. At the same time, we find a particular politics of knowledge operating in our daily practice as practitioners and researchers, a politics that prioritizes certain aspects and perspectives of science and research, while marginalizing other aspects and perspectives. Sundet (2021), using the concept of assemblage (Deleuze & Guattari, 1987/2013), points out that the contemporary knowledge situation in psychotherapy and mental health and its politics is a dominant mixture of three parts, the medical model, the randomized controlled trial, and New Public Management. This assemblage privileges certain practices in doing psychotherapy and mental health work. Assessment and the resulting diagnosis determine the choice of treatment to be used in an individual case of therapy. This is linked to a dominant perspective on research and knowledge production where the randomized controlled trial with generalized, group-based knowledge as its product reigns supreme. These two sets of practices in turn privilege the standardization of practices within theory-specific therapeutic methods. Theory specificity is necessary because theory with its explanations for why the problem or illness arose and what will ameliorate the predicament of the client enables manualization and principle-based practice. This approach to psychotherapy and mental health work and the use of research-based knowledge has had unforeseen political consequences. Central to New Public Management is the standardization of practices and the documentation that this standardization has been followed. Despite being an ideological expression of neoliberalism with its market orientation as a solution to most problems and challenges, New Public Management ends up representing strong and dominating control strategies and practices (Han, 2017). The “free market” is turned into a “controlled and restrained market,” where only those methods and their defined practices that are named “evidence-based psychological methods and practices” are accepted into the “market” of public health care. In practice, this means that the clinical and practical autonomy that psychotherapists have enjoyed has now changed. In Norway, the state is the arbitrator of New Public Management in national health care, which has now entered the therapy room through guidelines, requirements, and orders on how to do psychotherapy and mental health work. However, we clearly see in daily practice that the current situation still involves a mixture of state-governed content and the “old” liberties and autonomy of psychotherapists for the individual client in psychotherapy and mental health work. Our worry is that we experience in our daily work a tendency to strengthen the dominant assemblage described above.

Based on our use of an ontology of difference that privileges difference over identity, exemplified by the focus in modern developmental psychology on variability, diversity, and difference as pervasive at the level of people, we need an assemblage that can include these elements and accommodate the diversity that psychotherapists encounter in their practice. Sundet (2021) suggests an assemblage that is based on the priority of difference in psychotherapeutic and mental health work. This assemblage also has three parts. The first concerns knowledge that moves away from a hierarchy of research methods with the randomized controlled trial on top, privileging a network of methods that together produce knowledge. This does not mean that the knowledge produced by randomized control trials is rejected, only that it is transformed into a non-arborescent position within a reorganized assemblage. The second part is the valuing of multiple forms of research-based knowledge, where diagnosis is only one example. Other examples are collaborative and recovery-orientated practices generated through qualitative research methods (Klevan et al., 2023; Sundet et al., 2020a, 2020b). Finally, this requires organizations that are willing to include a diversity of perspectives and practices. In our experience, such diversity is best addressed by increasing the autonomy of clients and professionals in therapeutic work and increasing access to generalized knowledge. Stated differently, we would privilege what is done and decided by the participants in collaborative work, while also being closely involved with generalized knowledge as a reservoir and tool for what these encounters could entail. Generalized knowledge in the form of theory-specific therapies and their content of practices, principles, and perspectives suggests practices and what to do; they never decide what should be done. For us, an ontology of difference points to our experience as therapists, researchers, and teachers that there will always be difference, while we always remain aware that “Difference lies between two repetitions” (Deleuze, 1994, p. 101). This means that there will always be uncertainties and situations of not knowing what to do. Therapists must therefore be trained to encounter the unexpected when working in situations defined by elements that are radically new and never before encountered.

As stated above, when reading A Thousand Plateaus (Deleuze & Guattari, 1987/2013), we find that the authors systematically work with conceptual pairs, bringing them together as either connected and affecting each other, or as rearranged into a new assemblage. Affirmation of difference is central and avoids turning conceptual pairs into oppositions or dichotomies. The relationship between the two assemblages described above can therefore be expressed as a meeting between assemblages in a relationship where they both affect and are affected by each other. There is a balancing of their different aspects, perspectives, and practices. Deleuze and Guattari (1987/2013) urge for experimentation. We cannot know in advance whether an assemblage will turn out to be suitable for us or not, whether it will be helpful or harmful. However, Deleuze and Guattari do not take experimentation lightly (Adkins, 2015). They emphasize its dangers, and we would argue that there are similar risks in experimenting when we encounter people in mental health and substance (ab)use. Thinking in terms of assemblages forces us to think somewhat differently from the way we claim we are accustomed to:

. . . the family assemblage would appear to be the most effective device for arresting the anthropocentrism of much recent work in family studies, without obscuring altogether the mix of human and nonhuman interactions that shape family life. (Price-Robertson & Duff, 2019, p. 1040)

A family assemblage does not necessarily prioritize the human being or even stability. Rather, its most important features are openness, heterogeneity, and change. Anything, whether non-human or human, can be part of a family assemblage, and couple with it or decouple from it (Sælør & Bank, 2025). Yet, as Price-Robertson and Duff (2019) point out, “a family assemblage differs from other assemblages in that it coheres around specific functions or human relationships, most notably childrearing or intimate relations” (p. 139). Therefore, an approach to families as assemblages does not mean discarding any traditional idea of what a family can be, and to us it opens up more possibilities. The lamb (despite its unfortunate fate), or even the kitchen table, may pave the way for new attempts at supporting families who seem to get stuck, and speaking of stuckness, is anything ever actually completely stuck? “No,” most people would say, yet many who have encountered people who struggle could probably recognize the feeling. Yet, almost parallel to M. White (2007), and thinking with Deleuze, being stuck, or even in the same situation, is not an option. No matter how “repetitive” patterns of behaviour might seem, there is no such thing as sameness, there is only difference. Grasping and holding on to the idea that makes a difference is what matters. Questions such as “What should we do?” are no longer meaningful; instead, we might wonder “What might we become?” (Adkins, 2015, p. 246). Central to this way of viewing the relationship between science, research, and practice is the fact that there is a difference or gap between generalized knowledge and practice, and that in the present moment of therapy the participants in the therapy should be the judges and executioners of what they find best to do. In such a relationship of privileging practice in the present moment is the act of experimentation. This brings us back to ethics.

Closing words: Ethical realism and the privileging of practice

As we have defined “ethical” as an ethical realism, we are in the hands of the other, the one who is exposed to our practices; the other decides what is helpful. In every part of psychotherapy and mental health work there is an element of uncertainty. This uncertainty presents itself as differences of degree. There is always more or less uncertainty. This means that there will always be an aspect of experimentation in psychotherapy and mental health work:

. . . problems are inseparable from a power of decision (. . .) grounded in the nature of the problem to be resolved . . . a throw of the dice, the questions are the dice themselves; the imperative is to throw. Ideas are the problematic combinations which result from throws (. . .) To abolish chance is to fragment it according to the laws of probability over several throws (. . .) By contrast, the throw of the dice affirms chance each time. The most difficult thing is to make chance an object of affirmation . . . (Deleuze, 1994, pp. 258–259)

Chance and uncertainty invite experimentation. At the same time, one must experiment with great care. This is especially important in situations of the uncertainty of not knowing and where experimentation is often our only option. The chance aspect of uncertainty speaks to the fact that we cannot predict where our experiments will lead, which is why they must be done with great care. Now we are all capable of feeling that we are being careful, but the recipients of our assumed carefulness might not feel it in the same way. On the contrary, our good intentions might be felt by our clients to be negative or even as violence, and our judgements as professionals or private citizens to be avoided as untrustworthy. This is not because we are bad professionals, but simply because we are human. In psychotherapy, this predicament has been taken seriously through patient-focused research and the use of routine outcome monitoring (Lambert, 2010), i.e., the use of service user feedback on both the process and outcome of therapy, where the scores on standardized feedback forms are seen as conversational tools (Sundet, 2012, 2014), with the aim to ensure that clients find our practice helpful and not detrimental. Ethical realism therefore necessitates a perspective on psychotherapy and mental health work as an activity involving collaboration and dialogue (Andersen, 2021). This means the reciprocal exchange of ideas, feelings, and experiences concerning the practice we participate in and the question of whether this actually is helpful for the people seeking help in their everyday lives. An ontology of difference points to a view of reality where we will always encounter difference. The paradox of our project “Return to reality” (Bøe et al., 2024) is that everything stated here has the potential, like everything else, to block and come between the reality of the other and us as therapists and researchers. The idea of stable ground in life will then always end up as a continuous journey of becoming.