Having situated Heidegger’s thought in the epistemological scheme outlined by Foucault in his Les mots et les choses, we can discern not only its general contours, but also its limitations. We may even think of possible ways to transgress the limits of the ontological analysis of human existence and try to see mental disorders in a different light. It might be therefore effective to use the critical potential of Les mots et les choses to a maximum.

In the following chapter, Heidegger’s critique of natural science and its domination in the area of psychiatry, as it is formulated in his Zollikoner Seminare, shall be confronted with Foucault’s epistemological analysis of the classical thought that is conducted in Les mots et les choses and with the picture of classical medicine that Foucault presents in his Naisannce de la clinique. This confrontation brings to the fore the Cartesian idea of mathesis universalis which functions as a general matrix of scientific thought. The play of conceptual identities and differences based on the general matrix of mathesis universalis, however, leaves no place for the individuality of human existence. To grasp the individuality of human existence, both phenomenology and medicine must turn away from the conceptual scheme of mathesis universalis and from the classical notion of thought. Together with the individuality of human existence, phenomenology also uncovers the phenomenon of the lived body which reflects the psychosomatic nature of human existence. In his Zollikoner Seminare Heidegger then integrates the individuality of the human existence with the phenomenon of the lived body in the complex structure of being-in-the-world.

But before we reach the phenomenal structure of human existence, we must understand what prevents natural science from reaching the realm in which human existence finds itself. We need to examine methodological principles of natural science in order to discover the significance of the hegemony of natural science in the area of medicine. Despite an enormous progress in the effectiveness of medical treatment and the huge amount of information about the processes in human organism, medicine formed by natural science is, according to Heidegger, deceived in its approach to human existence by its very understanding of reality. Only if one arrives at understanding of what is real for natural science, is it thus possible to declare that there are any phenomena beyond the reach of natural science.

The inquiry into the methodic principles of a specific discipline is usually understood as examining the methodology of a scientific work in the relevant field of study. In the case of physics, which in Zollikoner Seminare serves as a model of natural science, the key role is played by scientific experiments and theoretical hypotheses. These two aspects of scientific work are essentially interdependent. Inasmuch as the scientific experiment is derived from an underlying theory, its results can lead to a revision of the given theory. With the help of the scientific experiment, it is to be shown whether or not the theoretical hypothesis corresponds to reality. In their reciprocal correlation, experiment and theoretical construction contribute to the co-operative discovery of nature. The two research methods share their scientific exactitude which is manifested in the use of mathematical forms and relations. What physical science finds in application of mathematics is an undisputed confirmation of its general validity and effectuality. The undertaken experiments and formulated hypotheses obtain the hallmark of objective truthfulness as long as they correspond to the spirit of mathematical exactitude.

However, a given means of research, which (just as an experiment or a theoretical construction) is meant to result in scientific knowledge, represents a method only in the “instrumental”¹ sense. From the purely instrumental conception of method Heidegger distinguishes method in the more original sense of the word, substantially different from the methodology of scientific inquiry. As the sense of the Greek words μετά and όδός (the “way from here to there” or the “way toward”) suggests, method in the original etymological sense denotes an approach by means of which the character of the examined area is revealed and delineated.² For the scientific theses and experiments to come into play at all, it is first and foremost necessary to gain access to the area under scrutiny. Only within the framework of an area open and determined by means of a certain method is it possible to invoke incontestable facts, while elaborating on theses and verifying experimentally their validity.

The question of method is therefore of outstanding significance within the realm of physics; the direction as well as the character of the inquiry is determined not by research practices, but primarily by the method that actually allows the implementation of these practices together with their mathematically exact treatment of facts. A similar conclusion is reached by Deleuze in his Différence et répétition when he considers the conditions enabling the repeatability of scientific experiments.³ As long as science presupposes the repeatability of processes observed under the same conditions, this is done not so much by applying mathematics to natural phenomena as by operating within the framework of mathematizable relations. Compared to preliminary access to the area under inquiry, the mathematical formality of the means of research is secondary, since the usage of mathematical forms can yield data only in the context of primary measurability. The realm of physical processes is thus always uncovered in advance with regard to their mathematical measurability.

Since the measurability of beings, as this is presupposed by exact science, entails comprehension of a purely quantitative character, physics must disregard the qualitative richness of life and focus exclusively on its mathematically apprehensible factors. Natural entities, stripped of their semantic potential, remain merely the sum of quantitatively recordable and mutually comparable data. However, the impact of the presupposed exact measurability of things is not restricted to their simple quantifiability. What lies in their measurability is also the preliminary calculability of all processes under observation. That is to say, the changes taking place are pre-adumbrated so that different eventualities of their course are predictable.⁴

Besides, Heidegger’s exposition of the methodological principles of mathematical natural science shows that the prediction of changes is possible only under conditions that guarantee elementary regularity in nature. In order for such conditions to be met, there must take place idealization, which yields homogeneous space and homogeneous time. Without it the modern conception of physical science as realized by Galileo and Newton could never have been formulated. Galileo’s principal point of departure that posits the conditions of empirical inquiry is the supposition in which the occurrence of change is regarded as a regular change of the position of mass-points in homogeneous space and time. What is postulated in this supposition is also causality without which exact predictability would remain inconceivable. The scientific rationalism proper to physics is based on the belief that every occurrence must be the effect of some cause.

However, Galileo’s presupposition is something that cannot, unlike the theoretical hypothesis, be proven or refuted by means of undertaking an experiment, since it reaches the ultimate ontological foundations of mathematical physics. In order to comprehend the key principles of mathematical physics, it is necessary to explicate the ontological project that underlies its method.

Heidegger’s clarification of the ontological sense of the method of exact sciences derives from the understanding that as soon as there is the continuous motion of mass-points discerned in the process of change, every single thing ceases to be an entity that is present in itself and instead becomes an object. Consequently, the field proper to physical science is created by nothing other than mathematically noticeable objects concatenated in causal relations. Everything that defies this framework is automatically considered as uncertain and as not truly real. Certain, i.e. true, is only what manifests itself in the sphere of objects of observation with a mathematical index to the eye of the observing subject. Nature, articulated as a set of observed objects, is placed in relation to the thinking subject. The dichotomy of the mathematically conceived res extensa and res cogitans corroborates the vast extent to which the method of mathematical natural science is informed by Cartesian dualism. Even though the idea of mathematical natural science reflects not so much Descartes’ own philosophical system as the whole legacy of his epoch, Descartes still continues to occupy an exceptional place, since it was he who pondered mathematical physics in its ultimate foundations.

Although the objective status of natural beings can seem, with hindsight, thoroughly natural, Heidegger connects it with the historical change of European thought occurring in the seventeenth century. According to him, neither Antiquity nor the Middle Ages were familiar with such a conception of beings: whereas ancient culture comprehended natural phenomena in the sense of the Greek φαίνεσθαι, i.e. as something manifested by means of disclosing itself out of concealment, medieval thought viewed all beings as created by the God. In comparison with these views of reality, objectiveness means a certain modification of the presence of beings. Natural science is made possible by a change due to which natural beings are no longer conceptualized as present in themselves; their presence can be manifested only by virtue of the ideas of the thinking subject. Although the reality of nature is not quite denied or condemned to the sphere of mere seeming or “semblance”, the presence of natural beings is thus comprehended as re-presentation.⁵ What in effect is at stake here is the radical reversal in the understanding of being of natural beings – their being is inextricably linked to their representation in the subjective mind.

The foundations of mathematical physics are revealed even further in the 1935/1936 lecture series published under the title Die Frage nach dem Ding, where Heidegger tries to explicate the character of the mathematical order (das Mathematische) underlying Galileo’s and Newton’s conception of nature. Here, just as in Zollikoner Seminare, it is demonstrated that Galileo’s and Newton’s natural laws make sense only within the realm that is projected from the outset in terms of measurability and computability of natural beings. For nature to be intelligible by means of mathematics, it needs to be axiomatically determined as equally distributed spatiotemporal nexus of mass-points; therefore, what can be projected into the scientific picture are only bodies integrated into this nexus.

In view of the fact that Descartes had indeed been the one who in an exemplary way pondered what Galileo and Newton achieved in science, a mere glance at his Regulae reveals that the mathematical order, out of which modern physical science is derived, must not be conceived of as mathematica vulgaris, but rather as mathesis universalis. What is at stake is not mathematics itself, but rather a project of the factual essence of beings that allows for a neat classification and gradual transition from the elementary toward the most complex of knowledge. The mathematical order as the principal standpoint of mathematical natural science creates the grounding that allows for the division of unclear and complex sentences into simple theses and, by drawing upon these in a rationally intelligible sequence, results in an understanding of the complex ones. In the overall arrangement and composition of everything within the order of mathesis universalis lies the broadest foundation on which mathematical physics is built.

This matrix, claims Heidegger, is not only the origin of mathematical natural science and modern mathematics (Leibnitz’s discovery of differential calculus, etc.), but also Cartesian philosophy as such. Descartes’ philosophical system is arguably the fruit of deep reflections upon the mathematical order; as if the mathematical tendency in thinking had awoken and grasped itself by considering itself the criterion of all thought and devising the rules it brings forth. It is only on the basis of the mathematical order that the need arises for the discovery of the first, altogether indubitable thesis that could serve as the ultimate axiom for all other sentences, irrespective of what they address. The statement “I think therefore I am” can be the absolute foundation for the certainty of cognition only because it relies on mathesis universalis as the basic matrix of the seventeenth century thought. The objectification of all beings present-at-hand would be meaningless without it, for these are put in relation to the subject of the axiom “I think – I am”.

It is interesting to note here that the characteristics of mathematically organized knowledge mentioned above converges in many respects with Foucault’s picture of the classical episteme. As the epistemological investigation undertaken in Les mots et les choses indicates, the arrival of classical science in the seventeenth century marks a rupture in the history of European thought. Not that science would have only at this point acquired a sense of measure and order; what occurred was that an altogether extraordinary importance was attributed to the values which had to some extent already been acknowledged. What is characteristic of the epistemological field of classical science is that measure and order serve as points of departure as well as the ultimate imperatives of thought.

The example of Descartes’ Regulae clearly demonstrates that it is by virtue of the universal validity of measure and order that not only deductive derivation and clear, purely intellectual observation of a certain thing, but also the comparison between two or more things achieve a new formal status. Apart from comparing quantities for the sake of determining the arithmetical relations of equality and inequality among things, Descartes also acknowledges comparison by means of order, within whose framework the simplest term is found and from there also the progression from simpler to more complex elements. As the measurement of size or amount can be reduced to creating order (since arithmetic and physical quantities may be arranged into a continuous row), both of the types merely represent two different ways of determining the progression from the simple to the complex. Thus, Foucault concludes that it is the idea of mathesis universalis, of the overall, rationally observable order, that plays the key role in the classical episteme. No matter how prevalent mathematical formalism might be within certain scientific realms, the plane proper to classical knowledge is not the mathematization of all reality and the concomitant conversion of a qualitative difference into a quantitative one. The mathematization of the empirical asserts itself only in such realms of classical science as the Galilean and Newtonian physics, whereas the relation of understanding to the general order as proposed in mathesis universalis also concerns the non-quantifiable. Insofar as classical science as a whole shares some common characteristics, this lies, according to Foucault, in its preoccupation with what he terms “the calculable order” in the broadest sense of the word. The reference to Regulae also lays bare another consequence of general calculability: the possibility of an exhaustive inventory. Whether the issue under consideration is an exhaustive list of all elements of a given set, or a division of an observed field into specific categories, or an analysis of a sufficiently representative specimen, mathesis universalis always guarantees the possibility of an exhaustive inventory as well as a continual transition from basic levels of understanding to the most complex ones.

To remain within the field of natural scientific investigation: a good example of a science formed on the basis of classical episteme is so-called “natural history.” According to Foucault, this science that deals with the order in the realm of living beings relies on the idea of a universal calculus, without necessarily resorting to mathematical reductionism. Unlike mathematical physics, natural history does not restrict itself only to quantitatively detectable values and relations, but also records other visible traits of natural beings. However, even here, a substantial reduction of the investigated area still does occur. Natural history does not inquire into the hidden qualities, forces and abilities that had determined the direction of natural scientific inquiry prior to the seventeenth century; nature is here relevant only insofar as it is accessible to the observing gaze.

Even the utilization of such an extraordinary means as the microscope is no exception to this rule. The exposition offered in Les mots et les choses proves the contrary: the implementation of the microscope is conditioned by a systematic reduction of the scientific perspective. Smells, tastes, and tactile sensations – all become excluded from the scientific observation. On the other hand, what is overtly privileged is sight, the sense of clarity and extension. Nevertheless, even sight is not accepted without certain limitation: especially the perception of colors is suppressed to the very minimum and what stands in the forefront are lines, areas, forms and surfaces. To observe is thus to determine natural beings with regard to their form, number, size and mode of their placement in space. However, this space is not the natural ambience of living beings, but an abstract space out of which all vital relations have been excluded. Whether concrete pieces of knowledge are ascertained quantitatively, or by means of geometrical forms, or through exact description, it is always within a visual field reduced to pure extension. The theme proper to natural history is therefore extension in which natural beings are manifested. In this respect, natural history is not by any means remote from mathematical physics that finds a guarantee for the quantifiability of natural beings in their position within the realm of res extensa.

The epistemological affinity of these two scientific disciplines, which emerges from their connection with mathesis universalis, does not, however, reach beyond the emphasis on perfect clarity and controllability of knowledge. Whereas the Galilean and Newtonian physics relies on nothing but mathematically formalized methods, natural history is content with an exhaustive inventory and a description of natural beings, thanks to which a certain specimen in various situations can be depicted in the exact same manner. The key to a reliable recognition of a certain animal or plant is their characteristic trait. Natural history focuses on determining the characteristic traits, thanks to which it states the differences among natural beings and classifies them, dividing them up into genera and species so that every creature finds its own place in the natural scheme of things. As every category must stand in relation to all others, what is peculiar to a certain specimen cannot be recognized except on the basis of a classification of natural beings. An animal or a plant has no identity of its own; it is that which others are not, as it is discernible only by means of differentiation. To identify a certain specimen is thus to ascertain what it is that sets it apart from other species. Any identification of natural beings encompasses a whole chain of differentiations. When natural history assesses the determination of genera and species of empirical specimens, it is not guided by vague similarities among natural beings. It persistently analyzes the relations of their affinity solely by means of the notions of identity and difference. These notions, however, don’t only govern the natural scientific taxonomy; as arithmetical relations of equality and inequality, they are also to be found in mathematical measurement and comparison. Therefore, Foucault can indeed proclaim the classical episteme as a whole to be characterized not only by the universal science of order, but also by the search for identity and difference.

The structure of the classical episteme must have left its traces in many other disciplines, including medical thought – however, not only by means of the physicalization of the human body, as one might suspect, but in a manner much more subtle than that. The analysis of classical thought which is presented in Les mots et les choses shows that the idea of the body as a physical mechanism, as this is widespread thanks to the influence of Descartes’, has dominated medicine only for a relatively brief time period. Natural scientific thought found its fulfillment in medical science, but it was natural history rather than mathematical physics that provided the model for scientific thought in this area. Its influence on medical thought is traceable on the pages of Naissance de la clinique, where Foucault addresses the so-called classificatory medicine. Similarly to natural history, classificatory medicine cannot do without a taxonomical system, within whose framework diseases are classified and hierarchized into various genera and species. What is important for its concerns is not so much the mechanical functioning of the corporeal apparatus or exact measurement of its blood pressure and temperature as the precise diagnosis of the type of disease and its ranking within the classifying system of diseases. The task of the classificatory medicine is to discern in the vast profusion of symptoms certain traits, to differentiate them from other pathological phenomena and to undertake their precise identification. In quest of the precise identification of pathological changes, the medical gaze functions as an instrument of scientific cognition that reveals, on the basis of the botanical model, the rational order of disease. The understanding of this “pathological garden,” a reliable knowledge of specific types of diseases and their mutual differences, functions as the foundational guideline for the doctor and, at the same time, as the indispensable prerequisite of a successful treatment. Whether classical medicine conforms to natural scientific classification or to Cartesian mechanicism, it never loses its elemental relation to mathesis as the universal science of measure and order.

In the light of these observations, Heidegger’s evaluation of the natural scientific mode of reasoning that is presented in Zollikon Seminars requires a certain adjustment. It is not problems of mathematical physics, but rather the foundational character of the mathematical project of beings as such that is to receive attention. In relation to the primary mathematical project, physics remains only one of the realms in which mathesis universalis has shaped itself as the cardinal standpoint to beings in general. Heidegger himself is very clearly aware of it in his Die Frage nach dem Ding where he stresses that the question of whether the utilization of mathematical procedures is indeed justified with regard to immediately present nature is not so important as the decision concerning the verification and limits of the mathematical order as such. It is not enough to confront the will to render nature quantifiable on the one hand, and nature essentially recalcitrant to it on the other. Behind the dilemma between mathematical formalism and the clarifying view of natural beings looms the question of limits beyond which the idea of mathesis universalis loses its justification.

From the perspective of the mathematical order itself the critical reflection on mathesis universalis may indeed seem to be a highly problematic undertaking. The mathematical order as the overall arrangement and distribution of observed beings has no limits, as it concerns both quantifiable and unquantifiable beings. Rather, mathesis universalis itself, from which not only mathematical natural science but also other scientific fields including philosophy evolve, is what determines the limits of scientifically exact reasoning. After all, any conceptual thought outside of the frame of measure and order is impossible, and so is any kind of science!

However, before accepting this presupposition, it is necessary to clarify what is understood by conceptual thought. In Zollikoner Seminare, the special position and function of scientific concepts receives careful scrutiny.⁶ Scientific thought, derived from the mathematical project of beings, requires in the first place that the concepts should be thoroughly unambiguous. Any ambiguity is to be excluded by means of a clear definition of every single notion. A correct definition proceeds in such a way that characterizes an entity by means of primary generality and secondary specificity; a general definition of an entity is accompanied by a characteristic trait that differentiates a given entity from other entities of the same kind. Definition thus proceeds from a higher category to the delineation of a specific difference. By virtue of this procedure, it is possible to single out and delimit one entity as opposed to all others.

So far, a conceptual definition wouldn’t be different from the way in which the Ancient thought used to differentiate various categories of beings. What is important, however, is to realize that conceptual thought as constituted on the basis of mathesis universalis is inextricably linked with representation. Heidegger claims a concept to be a re-presentation of something. The very word “concept” (der Begriff) inherently echoes “capture” or “concentration” which becomes, on the basis of the mathematical project, a representation of something. However, what is represented within the framework of conceptual representation is not a singular entity, but that which is common to all beings of a certain type. This representation is what remains identical in all individual cases.⁷ Only with regard to identity that is contained within every scientific concept is it possible to comprehend individual beings as representatives of relevant species. Although a concept is a representation of what is identically the same, it is still impossible to speak of this identity in positive terms. The identity represented in a concept has a sense only in relation to differences arranged within the overall system of understanding. Thus, the structure of mathesis universalis within the framework of conceptual thought is manifested as a complex order of identities and differences.

Nevertheless, conceptual thought grounded upon mathesis universalis runs against its limits once it is expected to comprehend the unique or the ambiguous. Since every notion must be absolutely unambiguous, it cannot grasp reality in its multitude of meanings. Faced with an ambiguous situation, the scientific notion becomes a hindrance in thinking. The same applies to every thing that needs to be shown in its irreducible singularity. To grasp what is peculiar to one single entity by means of concepts that assert themselves within the framework of mathesis universalis is altogether inconceivable, for their function is to highlight that remains identical in many beings. Even though abstraction as such does not quite explain what brings about the uncompromising unambiguousness of scientific notions, the necessity to disregard all singularities remains a side effect of conceptual thought. Any singularity gets lost by necessity in the interminable interplay of identities and differences.

It is this problem that Foucault alludes to while considering in his Naissance de la clinique the ambivalent attitude that classificatory medicine takes toward human suffering: as long as the view of medical science aims to penetrate through the plethora of pathological symptoms to their invariable foundation, it must suppress the uniqueness of every individual case and highlight what is common to all cases of the same kind. In order to pinpoint the basis of pathological disorder correctly, classificatory medicine must keep its distance from the individual experience of the patient and bracket all unclassifiable factors such as innate dispositions, temperament, or age. A qualified medical treatment cannot do without a perfected command of the classifying system of diseases that serves as a preliminary guideline of cognition, whereas the patient’s individuality is merely a negative attribute of the illness. Rather than the personal uniqueness of the patient and the unmistakable nature of his individuality, what is really important is the precise identification of the disease and its differentiation from all other elements of the nosological system. The individual side of human ordeal, including the peculiar multivocal nature of the space in which the doctor meets the patient, is thus bound to stay in the background of theoretical interest. Although classificatory medicine does not remain altogether blind to these phenomena, this is not due to its methodical effort to identify and differentiate the various kinds of pathology, but rather in spite of this.

Since Cartesian medicine is no less dependent on the clearly structured schema of identities and differences, the same applies to it as well. One might object that Cartesian philosophy at least maintains a relation to individual experience that is echoed in the foundational tenet of “I think.” However, as Heidegger observes in Die Frage nach dem Ding, the “I” as based on the mathematical order and promoted to the paramount status of the thinking subject contains nothing particular or unique. The subjectivity of the “I” lies only in the sheer necessity of its presupposition. In every utterance or act of thinking there is always presupposed the ego that thinks. The ego is what is always already present prior to any representation. Thus, the basis of the Cartesian “I” is not the individuality of a specific human being, but the permanent presence of the thinking subject. The “I” means nothing more and nothing less than res cogitans, out of which all qualities except for the ability to think have been abstracted.

Of course, the ability to represent is not restricted only to conceptual determination. Another mode of representation is to be added to the conceptual utterance, and that is sensual perception. In both cases, something is rendered present for the conscious “I” by means of representation. Although this “I” does not have to be always explicitly aware of itself, it must necessarily retain its substantial identity. In relation to the “I” regarded as the subject of thinking, all other things appear as objects. The objective status of the observed beings is nothing given per se, since it follows from the turning point in the understanding of the being of beings as brought about by Descartes on the basis of the mathematical order. The so-called objective reality is an ontological construct arising from the quest for the absolute certainty of understanding. As soon as this certainty has been found in the constant presence of the substantial “I,” all beings lacking the character of the “I” are regarded as objects.

It is nonetheless disputable whether such an ontology can in fact be adequately applied to human being. The exposition presented in Zollikoner Seminare most resolutely testifies against this possibility. Heidegger does not miss a single opportunity to point to the fact that an ontology that understands being from the viewpoint of representation does not do justice to human existence. In his opinion, the peculiar character of human existence cannot be understood as long as human being is rendered an object about which scientific thought obtains data by means of conceptual representations. The inadequacy of this approach is demonstrated by the fact that human experiences and moods are not objects within the sphere of res extensa, something which was already known to Descartes. It is insufficient to proclaim human existence to have, in addition to its somatic part, also a part pertaining to the realm of res cogitans, and go on to examine their mutual effects. The multivocal shades and minute nuances of mental life cannot be understood once converted into representations in the consciousness of an abstractly conceived subject. The same applies to the human body which can be imagined as a physical mechanism and whose components can be subjected to physiological inquiry, but only at the cost of losing all human uniqueness. What then remains of it is an object torn out of its relation to its environment, an object resisting inner development and changes that have to do with aging. At best, ageing can manifest itself as dilapidation or imperfection that science may manage to remedy one day, but not as a natural principle of life.

Although this reduction concerns every biological organism, it is most clearly conspicuous in relation to human being. Natural history and mathematical physics, which both rely on mathesis universalis, can perceive human being only as a natural species or as a mathematically intelligible object. However, once the question is raised as to who human being is and how it exists, both disciplines are faced with the limits of their possibilities. The way in which human being as the unique individual relates to things, to others, to itself and to its own end remains by necessity beyond the reach of their understanding.

In general, one can say that this limitation applies to all scientific fields based on mathematical project of being of beings. The mathematical order asserted itself within Western thought not because it enabled us to unveil the peculiar character of human existence, but because it guaranteed a lucid classification of all realms of knowledge, irrespective of the specific character of the beings under observation. The universal order based on the idea of mathesis universalis is not only a visible arrangement of things, not only a symmetrical configuration of their proportions and relations, but the modus of being attributed to them prior to every empirical inquiry. The question of the peculiar character of human existence is neither the central theme nor the guideline of scientific thought. It is therefore no wonder that human existence, recalcitrant both to classification by means of conceptual identification and differentiation, and to preliminary objectification, stakes out the limits beyond which the mathematical order can no longer guarantee an adequate understanding.

With regard to the central role played by the idea of mathesis universalis within the whole scope of classical knowledge, it is self-evident that to inquire into the boundaries of the validity of the mathematical project of beings is to contemplate the outer limits of the classical episteme. The universal science of measure and order acknowledges only its inner boundaries, beyond which all non-scientific opinions and confused utterances are brushed aside. Nevertheless, the mere fact that classical science has its historical beginning implies that one day it is bound to reach its end. The idea of universal calculability as born in the seventeenth century does not necessarily have to perish together with it, but it most definitely must be deprived of its claim to absolute validity. In that very moment, the question of the limits of the universal science of measure and order becomes topical.

It would therefore be inane to regard Heidegger’s critical reference to the inadequacy of all attempts at thematisation of human existence by means of a method that is grounded upon preliminary objectification and conceptual identification of observed beings as an expression of ill-concealed enmity to science as such. Heidegger himself refuses such a suspicion when claiming: “By no means should our discussions be understood as hostile toward science. In no way is science as such rejected.”⁸

However, what remains questionable is that the ideas grounded upon mathesis universalis assert themselves within a field where human existence is at stake. Pushing into forefront the question of human existence, Heidegger strives for nothing else but rendering human existence understandable and explicable out of itself. Judged by the prism of Les mots et les choses, an attempt at directing attention to what concerns man himself and what by necessity eludes him in the sieve of objectifying ideas reflects the rupture between classical and modern knowledge. On the epistemological plane, the philosophical critique of the mathematical project of beings, especially as far as its principal incompatibility with the human way of being is concerned, appears possible only by virtue of the rupture whereby the theme of human being breaks into the visual field of scientific inquiry. As long as classical discourse fuses the representation and the being of beings with the same certainty with which the cogito allies with the sum of the thinking subject, the question of human existence cannot be raised. The formulation of the question of human existence is thus accompanied with the retreat of thought from the space of representation and the breakup of the general project of mathesis universalis. With the arrival of modern episteme, a rearrangement occurs within whose framework the structure of the calculable order, and together with it the formal disciplines such as mathematics and physics, stands on one side, and in opposition to it is the realm within which interpretive disciplines such as hermeneutics and clinical diagnostics evolve.⁹

However, the very breakup and substantial narrowing of the sphere of mathesis universalis does not guarantee an adequate thematization of human existence. The mere discovery of the theme does not mean the final victory, but rather poses an interminable task. For the adequate approach to human existence to be safeguarded, it does not suffice to merely register details and personal peculiarities of individuals. Heidegger is well aware of the fact that attention to the human individual and its unique qualities alone cannot lead to anything quite yet. Insofar as human existence is to be thematized in an adequate manner, it is first of all necessary to find a method that would discover the way into the realm where human existence can be encountered as such.

This path cannot be procured by empirical observation, but only by philosophical inquiry. A real, and not merely illusory, approach to human being requires a philosophical method that would be fully appropriate to the specifically human way of existence. The demanded method must strictly adhere to the mode in which human existence shows itself, and leave it at that. A method that meets the given criterion and allows for the thematization of human existence without inadmissible distortion or confusion is found in phenomenological description. According to Heidegger, phenomenology provides us with the optimal approach to human existence whose reach qualitatively surpasses the mode of thematization based on mathesis universalis.

However, the peculiar mode of phenomenological description is to be strictly differentiated from a description used in, e.g., botanical classification. First of all, phenomenology is not a procedure for acquiring pieces of scientific knowledge, but a method in the original sense of the word, i.e. a way that opens a certain realm of beings. Moreover, human being from the phenomenological point of view does not manifest itself as a specimen of a certain species, be it a categorical determination of an entity traditionally defined as animal rationale. Unlike science shaped within the horizon of representational thought that reduces all phenomena to objects of conceptual comprehension, phenomenology strictly forbids such reductionism. Phenomenological description does not lie in the representation of facts stated in the sphere of res extensa; its orientation is rather subjected to manifesting every phenomenon in terms of what is peculiar to it. Since they are not representations woven into any well established network of identities and differences, and their sense is drawn directly from what they speak of, phenomenological notions can reveal both the uniqueness and the ambiguity of concrete phenomena.¹⁰ Although phenomenology is not devoid of the character of conceptual thought, its notions are not so much based on the uniform matrix of mathesis universalis as they are on the uniqueness and ambiguity of what manifests itself.

Inasmuch as phenomenology is led by the striving for thematization of pure phenomena, it remains to be clarified what is understood by the notion of “phenomenon.” Heidegger’s answer to this question is derived from the differentiation between the ontic and the ontological phenomenon. It is generally true that a phenomenon is what shows itself, but it can show itself to us in various ways. Therefore, phenomena shown to our senses are, according to Zollikoner Seminare, placed on the one side, and phenomena sensually imperceptible on the other.¹¹ Whereas the ontic phenomenon relates to sensually perceptible beings, the ontological phenomenon concerns the being of beings that can be observed only in its sense. The being of beings can be manifest only through thought that relates to it with understanding. Even though the being of beings does not show itself as such in the beginning, the preliminary evidence of its sense is a prerequisite for any ontic register. Compared to ontic phenomena, ontological phenomena therefore occupy the foundational position and are of primary philosophical importance. Since being as such often remains concealed behind beings that freely offer themselves to our attention, the task of phenomenology as Heidegger conceives of it is to bring being to its explicit manifestation.

The phenomenological effort to thematize the being of beings does not at all mean that beings are to be completely ignored. Heidegger is rather concerned with our relation to beings so that the being of these beings emerges thematically. This hermeneutic engagement in the relation with immediately manifest beings aims to overcome the obfuscation of ontological phenomena that remain hidden under a layer of philosophical tradition or merely filtered through it in the form of phenomenologically unclarified seeming. The need for penetrating to what remains unthought-of within the philosophical tradition necessarily leads to a revision of this tradition, and especially to a critical evaluation of the conceptual structures grounded upon the principle of mathesis universalis.

Heidegger’s critique of ideas derived from the mathematical project of beings asserts itself most conspicuously in the destruction of Descartes’ philosophical system. Against the unwavering certainty of cogito – sum that places being next to representation, Zollikoner Seminare focuses its scrutiny on the character of that sum. As Foucault in his Les mots et le choses claims that phenomenology is not so much a continuation of the tradition of Ancient thought as an expression of the rupture between the classical and modern episteme, the same applies to its Heideggerian version.¹² Despite the proclaimed return to the Greek conception of phenomenon as that which shows itself from itself, what is corroborated here is the original connection of phenomenology with the question of the human way of being, and together with it occurs also a certain consummation of the analytics of the finitude of this being. Instead of the objective observation of a human being or a retreat to a predetermined, closed-off subject, the phenomenological approach to human existence entails a hermeneutical entry into an open relation with what encounters and addresses us. The starting point of the phenomenological approach to human existence is thus our unmediated sojourn (der Aufenthalt) with beings. The exceptional character of man’s sojourn (der Aufenthalt des Menschen) is not given by occurring at some place, but rather follows from an openness toward the world that is peculiar to human existence. Our sojourn has an essentially worldly character, as it evolves within the significative whole of the world. Being-in-the-world must therefore be shown as the foundational ontological feature of human existence. In order to adumbrate the preliminary ontological structure of sojourning as formed by being-in-the-world, Heidegger uses a simple graphic schema¹³:

This sketch makes the point of suggesting that human existence has nothing to do with an isolated, withdrawn subject which only secondarily relates to wordly beings. What is essential to sojourning is its openness to the possibility of addressing beings that manifest themselves in the horizon of the world. A verbatim translation of the German “sich aufhalten” (where “auf” refers to a certain openness, whereas “sich halten” means “to hold on to”) suggests that the ontological character of sojourning lies in its maintaining an open horizon of the world, within whose framework significative and motivational connections present themselves in the shape of concrete beings. In the context of a disclosed and cleared sphere of the world, the sojourn always relates to that by which it is encountered and summoned to act. The sojourn finds itself always already in the world and only as being-in-the-world can it relate with understanding to specific beings as to its own possibilities.

Since we relate to our possibilities not only spiritually, but unveil them mostly by its practical action, the question of the bodily character of human existence cannot be avoided. Should the human body be regarded as an entity occurring in a certain place in space, or is it to be comprehended from the viewpoint of the ontological structure of being-in-the-world? Heidegger resolutely opts for the second option when distinguishing the lived body (der Leib) from the corporeal thing (der Körper). The lived body is not a mere material given, but a factual expression of being-in-the-world. The facticity of our existence remains both in its openness to the world and in its bodiliness (die Leiblichkeit). The lived body is a natural center of gravity in our relating to possibilities around which the differences between near and far, up and down, right and left are organized. Corporeal things, on the contrary, have no relation to space at all, they merely occur in it.

The phenomenological description of the lived body can therefore not simply postulate it and go on to derive from this various directions and trajectories, but rather must persistently stick to the open spatiality of being-in-the-world. A dynamic transitional nature of the bodily existence can assert itself only on the basis of openness that characterises being-in-the-world. The peculiar character of this transitivity can be best illustrated by the fact that the boundaries of the lived body don’t align themselves with the boundaries of the body in the sense of a mere corporeal thing. Whereas our corporeal frame ends with our skin, the lived body transcends this limit.¹⁴ However, one can speak of a transcendence only in the phenomenal sense, since it reflects our ecstatic relatedness to surrounding beings. As hearing, speaking and seeing constitute an essential part of our lived body, its only limit is the horizon of our world. Unlike our corporeal frame whose content can change only by growing, gaining or losing weight, the horizon of our world is freely transmutable, and thus capable of vastly surpassing all tactile sensations, as well as receding in reverse into a single intensive feeling of physical pain. What then remains after our death is only Körper, whereas our lived body ends together with our existence.

If natural science derived from the mathematical project of beings neglects the lived body, it is because it mistakes it from the very beginning for a corporeal thing, ontologically interpreted as an object. With the help of measurements, causal-mechanical schemata and conceptual categorization, one can indeed track down many objective items of knowledge concerning the human body, but never understand the ontic aspects of the lived body. Pain, blushing with shame or weeping, all elude the view adjusted to facts represented within the realm of res extensa, and yet they remain inherent to the basic possibilities of our bodily existence. In order to find adequate access to these possibilities, it is not enough to consider them as traces of human psyche; it is rather necessary to understand them as various modes of being-in-the-world. After all, a sudden blush is not an expression of psychic processes, as it makes sense only in relation to some specific situation in the world. The same applies to all physical postures and gestures. All ontic phenomena that express our bodily existence have thus neither a psychic, nor a somatic, but a psychosomatic character. To split human existence into its psychic and somatic parts is for Heidegger to completely fail to regard their original whole as formed by being-in-the-world.

What is also bound with the overall unity of sojourning with beings is the fact that the lived body, unlike the anonymous corporeal thing, is endowed with a genuinely individual character. The lived body is always mine; or rather, I am my own body. It would be utterly absurd to contend that the eye sees, the mouth speaks, the hand works and the brain thinks, since it is always I myself who sees, speaks, works and thinks. Equally erroneous would be the assumption that the lived body presents a sort of substratum upon whose basis human individuality is sustained. This is evident from Heidegger’s statement: “If the body as body is always my body, then this is my own way of being. Thus, bodying forth is co-determined by my being human in the sense of the ecstatic sojourn amidst the beings in the clearing [gelichtet].”¹⁵

That human being exists as an open being-in-the-world does not mean that its existence disintegrates into an incoherent welter of sensations, gestures and attitudes. In spite of remaining open to an address on the part of innerworldly beings, my relation to these beings is necessarily one and the same with the performance of my own existence. When coining in his Sein und Zeit for man’s sojourn the notion of “being-there” (das Dasein), Heidegger says nothing of it except that it is myself, that being of being-there is in each case mine (je meines).¹⁶ And the task of the ontological analysis of being-there is to reveal the locus of its peculiar individuality. Since being-there never has the character of an entity which is present-at-hand and whose qualities can be simply postulated, its individuality cannot be determined by marking out an essential substance. On the contrary, the ontological analysis must display the self in the various modes of its existence. That being-there exists as an individual follows only from the ecstatic nature of its relatedness to beings which it encounters. Heidegger’s concept of the individuality is thus sharply different from the Cartesian conception of the “I” that remains identical throughout the incessant succession of its cognitive acts. While the subjective consciousness remains cut off from the world to which it is related, being-in-the-world ontologically belongs to our self. The “I” understood as individual being is not an isolated, abstract subject, but rather the specific “I am in the world.”

Since individual existence does not remain detached from change, but actively engages in it, the difference between such existence and the Cartesian subject most conspicuously manifests itself on the temporal plane. The Cartesian “I” is posited as what is always already present-at-hand; that is to say, it is a substance that cannot be affected by time. The existential constancy of the self is, on the contrary, essentially connected with time. As Heidegger puts it, “[t]he constancy of the self is temporal in itself, that is, it temporalizes itself. This selfhood of [being-there] is only in the manner of temporalizing [Zeitigung].”¹⁷ Ultimately the phenomenological description of the self thus extends to temporality which gives our existence its original sense. The ecstatic relatedness to beings in which our existence evolves is not “carried” by anything other than its own temporality. The ecstatic relatedness to beings that binds the future, the having-been and the present into one whole, ensures the essential coherence of existence, thereby endowing it with its individual constancy.¹⁸ Much as this individual constancy remains open to change and existential rupture, it is also an expression of the fact that human existence always somehow understands its being, that it comprehends it as its own and, to some extent, as always the same.

The phenomenological description of the temporal unity of existence thus arrives at the idea of sameness which is irreconcilable with the epistemological character of classical rationality. Sameness, which encompasses in itself both constancy and change, which steps out of itself and becomes other, is according to Foucault’s testimony one of the crucial components of modern episteme.

However, one must not forget that phenomenology is not the only mode of thought that on its quest for what is not identical with itself gains an understanding of individual life in its changes and duration. The revelation of human individuality is not a prerogative of only philosophical inquiry, but occurs in the much broader context of European thought, which has had its repercussions also within the field of clinical medicine, as it is documented in Naissance de la clinique. Ever since the eighteenth century, that is to say, with the arrival of modern episteme, medical thought has become increasingly appreciative of the importance of all unclassifiable factors that had thus far been supplanted by the classifying system of diseases. Individual dispositions, age or way of life have moved into the focal point of medical attention and, together with them, the specific human individual sees the light of day. Thanks to the reversal in the relation between the classifiable and the unclassifiable, the human individual becomes visible in its own singularity. Thus, according to Foucault, medicine is transformed into a science dealing with the ill and healthy individual. In spite of the fact that within the nosological system, the model of natural scientific classification is still utilized, there nonetheless occurs a shift that enables clinical medicine to penetrate into the inside of the human organism and reveal the dark depth of bodily existence. Only when pathological anatomy assumes the pivotal position within medical knowledge can medicine arrive at an understanding of a living organism, its development, aging and death. Rather than a classificatory table of diseases, what should henceforth be the focal point of medical interest is to be found in the various ways in which an ill organism resists or succumbs to pathological decomposition. The virtual boundaries between the disease and the patient are gradually wiped away to the point of vanishing, so that what remains is the patient and his pathologically transformed existence. Classical medicine of natural species is thereby changed into the medicine of pathological reactions.

The fact that empirical investigation of human health and disease, similar to phenomenological description of temporal sojourning, addresses the individual character of human existence does not imply that Heidegger’s ontological analysis has nothing to offer to modern medicine. What gives phenomenology the hallmark of exceptionality is both its understanding of the principal role of temporality and its sense of the integrity of the being-in-the-world that enables it to thematize complex psychosomatic phenomena without having to derive them from the functioning of the biological organism. The phenomenon of the lived body that obtains its sense against the backdrop of the overall structure of being-in-the-world is substantially different from the anatomical constitution of the human organism or the structure of the organic tissues. Even though modern medicine has marked a breakthrough in the understanding of inner development of organic structures, the lived body still remains inaccessible to it. The lived body, which forms an integral component of the ontological whole of being-in-the-world, is the key to the understanding of many psychosomatic disorders about which clinical medicine is still in the dark. Thus, the articulation of being-in-the-world can be regarded as the most important result of the phenomenological method for medicine.

The phenomenological approach to human existence is highlighted in Zollikoner Seminare especially in connection with psychiatry and psychotherapy which gradually free themselves from postulates determining mental disorder as a specific entity, situating it within the framework of the psychic totality of man instead. The phenomenological method can provide these disciplines with the needed philosophical foundation enabling them to adequately thematize not only the unity of psychic acts, but also the original unity of psychosomatic totality. With regard to the topic of the present study, we shall focus on the question of how, on the basis of ontological description of being-in-the-world, the nature of psychopathological disorders can be understood.