Transcendental Phenomenology and the Debate on the Relation Between Science of Nature and Metaphysics
What more or less explicitly underlies the different positions reconstructed in Chapter 1 is a certain account of the nature of knowledge, of the “cognitive bond” between subjectivity and the world. Such an account of knowledge determines a philosophical “interpretation” of the being of the world, which, in turn, assigns to physical theory a specific task and method. Conversely, in each case, the resulting conception of physical theory reveals how the relation between subjectivity and the world is understood. As we have already noticed, one should not forget that, no matter their degree of scientific sophistication, these positions remain within the compass of the philosophical alternatives bequeathed to us by modernity from Descartes to Kant. Transcendental phenomenology aims to overcome such positions, not by providing yet another “interpretation” of the being of world, but by elucidating its sense according to an intuitive method. By removing such interpretations, transcendental phenomenology undercuts also more recent epistemologies developed at the end of the 19th century as well as their progeny.
The point of departure in Chapter 1 was provided by the doubts raised by Du Bois-Reymond about the metaphysical value of the mechanistic worldview. A radical solution to Du Bois-Reymond’s unsettling ignora-bimus was Mach’s position, which aimed to free science from any “metaphysical mythology” and, consequently, to deny the existence of any alleged limitation to our knowledge. Such a point of view, firmly rooted in the tradition of Hume’s empiricism, could not be in any way satisfactory for Husserl, and it is surprising that some interpreters have failed to acknowledge this fact. As is well known, Mach’s account of perception is totally unacceptable in light of Husserl’s theory of intentionality, which in turn provides the basis for his conception of knowledge. Mach, just as any phenomenalist, fails to acknowledge the distinction between the immanent data of experience and the objective properties belonging to the experienced object.96 In the language of the Ideas, the former are the hyletic data, which, animated by the noeses, give rise to the objective properties that are the correlates of perception. By reducing the thing of perception to an associative complex of sensations, Mach misses the intentional character of consciousness. Only by virtue of this confusion could he claim that physical bodies are convenient signs or symbols for complexes of sensations and that “the world consists of colors, sounds, temperatures, pressures, spaces, times, and so forth.” This mistake determines, in turn, his conception of the task and method of physical theory. If the things of perception are just fictions that, no matter how instinctively, we devise in order to summarize a large amount of experiences, if they exist “only in thought,” the task of the theoretical determination of
The Transcendental Constitution of Nature 185 such things becomes meaningless. There are no true intrinsic properties of such things. Consequently, physical theory cannot but continue in a systematic way the economic function already at work in our prescientific life, i.e., summarizing and connecting sensations in a systematic way.
According to Husserl, sensations are not signs or symbols of things, either; rather, they are apprehended in such a way that an object can be adumbrated, an identical pole can announce itself in consciousness, without being an immanent component of it. Consciousness is no longer a complex of immanent elements, but a structure of directedness stretched between the opposite poles of the pure ego and the intentional object. One can thus appreciate that, whereas Mach sees the relation between actual and potential perception in terms of a lawful connection of sensations, Husserl identifies in the notion of horizon the essential feature of transcendent perception. The being of the thing perceived is thus constituted in the constant progress of experience. But, if the qualities of the perceived thing reveal a regulated dependency on the perceiver’s Leib, then the way is open for setting the goal of its theoretical determination after the manner of mathematical physics, to which, accordingly, the task of knowing the intrinsic properties of “physical bodies” is assigned. Finally, as intended sense, as constituted unit of sense, the perceived thing as well as its theoretical determinations, while not existing “only in thought,” are in no way beyond consciousness: consciousness has no outside.
While Mach’s phenomenalism, as much as the radical empiricist philosophy it derives from, ends up in the denial of the transcendence of the world, and in its reduction to psychological immanence, critical realism (and metaphysical realism more generally) misunderstands the sense of transcendence in an objectivistic way. In this chapter as well as in the previous chapter, I have explained in detail in what way, according to Husserl, this perspective rests on the failure to grasp the sense of the transcendence of the world (of its “externality,” so to speak) and the absurd views about the task of physical theory that follow. Here, I would like to draw some conclusions concerning the different resulting articulation between natural science and metaphysics. In order to do so, let us first recall Husserl’s early distinctions between different meanings of the term “space” (see Chapter 2, §1), viz. between (1) the space of prescientific life, (2) the space of pure geometry, (3) the space of the science of nature (or space of applied geometry), and, finally, (4) the transcendent metaphysical space, i.e., true space as it is in itself. We can now appreciate how transcendental phenomenology clarifies the relation between these different levels of spatiality. The space of prescientific life is the one in which the things of perception are situated. In this chapter, it appeared as an objective system of location that is not directly given to the senses, yet intuited on the basis of changes of location and acts of empathy. The identification of this space with the space of geometry yields the space of natural science. In virtue of this identification, the space of prescientificperception does not become the space of pure geometry nor does it disappear to give way to it; rather, the true spatial form of the world is defined as a Euclidean three-dimensional manifold that can manifest itself to us only through the space of perceptual intuition. This is the sense of its higher order transcendence, which grounds the possibility of identifying the things of perception with theoretical counterparts situated in the space of natural science. Once the theory of constitution has accounted for this identification and removed any possibility of considering the space of natural science as a symbolic representative of a space existing in itself and lying beyond the reach of our knowledge, once the transcendence of the space of natural science is elucidated, then such space can also be called metaphysical, according to Husserl’s definition of metaphysics as the ultimate science of reality. Similar considerations can be repeated concerning time and, thus, the entire spatiotemporal form in which each natural reality is situated.
Now, if we compare this result with the critical realists’ tenet that there are three “worlds,” the world of perception, the world of physics, and the real (metaphysical) world, we understand why, according to Husserl, there is, instead, only one world comprising two different constitutive strata. Once we realize that the true world in itself of the critical realists is an absurd metaphysical substruction, and once we realize that the world of physics is the objectivation of the world of perception, and once constitutional analyses have clarified the sense of this identification, the world of physics acquires also the metaphysical sense of the true world in itself. To be sure, this does not mean that the system of our current scientific theories is true. Rather, if this system is not affected by any internal incoherence, it corresponds to a possible true world in itself. The true world is described by one such possible system of theories, and it is in no way an unreachable in-itself that resides on a different ontological level. The true world becomes an idea in the Kantian sense lying at the endpoint of an infinite progress of theoretical determination. The task of physics is the endless horizontal objectivation, so to speak, of the world of perception, rather than the hopeless attempt to bridge the gap between subjectivity and an absurdly absolutized world in itself. Consequently, the claim of some critical realists that we can in principle access only the structural structure of nature (see Chapter 1, §4) and not its ultimate constituents also becomes meaningless.
Let us recall how, in Chapter 1, Du Bois-Reymond’s account of the limits of natural-scientific knowledge and of its total lack of metaphysical value prompted a vast debate in the scientific and philosophical circles of the time. It is now time to ask ourselves whether transcendental phenomenology has the resources to meet Du Bois-Reymond’s challenge. This is of course not something that, to my knowledge, Husserl has discussed anywhere, not even in a sketchy way that would indicate how a response should be given. However, a phenomenological solution to the riddle of
The Transcendental Constitution of Nature 187 the essence of matter is required to further clarify the sense of the phenomenological transformation of the sciences of facts into metaphysics.
Let us go back to why Du Bois-Reymond believed that we are unable to build a satisfactory notion of the philosophical atom, i.e., one that, in contrast with the physical atom, is not just a useful methodological devise, but also a metaphysical entity explaining the properties of matter. This argument, as I understand it, runs as follows. Du Bois-Reymond’s fundamental premise is that we are unable “to represent anything other than something experienced either with the external senses or with the internal sense.” In the quest for the fundamental components of the physical world, we start from matter as we perceive or imagine it, and we set out to divide it further and further. Two alternatives are open to us: if we simply halt the division at a certain point, we still have a chunk of matter that has the same properties as the one with which we started. Thus, no step has been taken towards the determination of the essence of matter: we obtain a physical atom that can at best help us to mentally decompose large objects in a convenient way. The other alternative is that we do not limit ourselves to halting the division, but, in virtue of a coup-de-force, we attribute to the small part of matter just obtained completely new properties that are not experienced with either the external or the internal senses. However, by virtue of Du Bois-Reymond’s premise, we obtain something that we are unable to represent, which leads to the classical contradiction of corpuscular philosophy. In other words, concepts such as “pointlike particle having a mass and a charge” or “extremely small and yet extended particles that are indivisible and infinitely rigid” are chimeras created by attributing to material entities properties that we do not experience (and, presumably, cannot experience).
Let us now set aside the problem, already mentioned in Chapter 1, that this argument assumes that physical explanation must necessarily be mechanistic. This is a factual problem that does not concern us here. The objection that can be raised from a phenomenological point of view is that Du Bois-Reymond’s fundamental premise is wrong. We are indeed able to represent something that we cannot experience with either the external senses or the internal sense, viz., idealizations. The difference between perception and idealization is completely absent in Du Bois-Reymond’s argument. The intrinsic determination of material objects is not reached by “halting the division at a certain point” and eventually postulating some mysterious properties, but by replacing such objects with ideal entities endowed with mathematical properties only, which fill a likewise ideal space. We obtain, in this way, a theoretical determination of what we experience that is different in character from what we experience. This distinction between perception and idealization, Husserl’s own reinterpretation of Descartes’ distinction between nature as object of imagination and nature as object of intellection, is such that the latter “is not, strictly speaking, describable, and no concepts ofimmediate experience can go to determine it.”97 It is thus pointless to worry about the limitation that experience and imagination set to our ability to represent an object. The internal coherence of such hypothetical inner nature of physical objects is, of course, not guaranteed a priori, nor is its intelligibility (as today’s philosophers of physics know all too well), but it will depend on the internal features of the relevant mathematical structures, not on whether we can make sense of it by means of perception and imagination.98 Perhaps pointlike particles or indivisible extended chunks of matter do not make physical sense, but this cannot be decided based on the power of our imagination. And if they do not make sense, then perhaps a space-time filled by different types of fields the quanta of which are elementary particles does, and this will provide a characterization of the inner properties of matter awaiting experimental confirmation. Indeed, among the coherent theoretical accounts, experimental results must (at least in principle) single out the best account, because such a characterization of the internal nature of matter is not an a priori, philosophical theory. I doubt that Du Bois-Reymond could ever prove that every physical theory must necessarily be incoherent if regarded as a tentative characterization of the inner structure of the material world.
Let us finally notice that these considerations show how Husserl’s account of the theoretical determination of nature does not require any metaphysical concept of matter. Materiality, as eidetic components of things, admits of a phenomenological analysis, but not matter as a substance of which physical objects would be made. Physics does not need the concept of matter: idealizations are not made out of matter, nor do they stand for anything “material” laying beyond them.
From the standpoint of phenomenology, there are thus no limits to the knowledge of nature, this being a consequence of the fact that nature is only a unit of sense constituted in perception and determined by idealizations. However, one could still question the phenomenological conception of metaphysics as the ultimate science of reality in a different way, from the inside, so to speak. If the theoretical determination of nature is possible by virtue of the manifestation of the objectively true nature “behind” the nature accessible to the senses, as Husserl sometimes says, why couldn’t one imagine that nature as determined by physics admits of a further layer of theoretical determination, yet of a different kind? Could physical nature, then, be just an appearance of another being that appears through it, and that would require another level of constitution? If this were the case, a science of nature, even elucidated by phenomenology, would not deserve to be called metaphysics, for it would not be an ultimate science of reality. However, this highly speculative possibility can be ruled out. In order to understand why, it suffices to recall that nature as it appears to the senses has to be determined by physical theory because it reveals its relativity to the Leib. The idealizations of such sciences, on the
The Transcendental Constitution of Nature 189 other hand, cannot in principle manifest any relativity to any contingent feature of the knowing subject because they are mathematical in character. As such, they enjoy a pure objectivity, which cannot be relativized to the contingent normality of a community of knowing subjects. To be sure, intellectual normality is required by the constitution of mathematical objectivity, as of any other objectivity," but such normality is not relative to the contingent features of the knowing subject. Rather, it defines the universal community of all rational subjects. A denial of this would imply a relapse into the kind of psychologistic interpretation of logic and mathematics that Husserl had criticized in the Prolegomena. Thus, the ultimate objectivity of the science of nature rests on the ideal, pure objectivity of mathematics and of logic. In conclusion, there cannot be any rational motivation to relativize the being of physical nature and to sub-struct another being that would be transcendent with respect to it.
This last consideration, I believe, contributes to clarify what Husserl meant at the end of the already quoted passage of First Philosophy: “the universe of the world, the universal theme of the positive sciences, acquires a ‘metaphysical’ interpretation, which means nothing other than an interpretation behind which it would make no scientific sense to seek another.”