The Oxford Handbook of German Philosophy in the Nineteenth Century

by Michael N Forster

  Reflective judgment compares given ideas with others when no general category is present. It does not, therefore, have to do directly with objects. It comes into play in science when, in connection with our experience, we encounter an idea that, because it is not an object that concepts can determine, stands outside the causal regularity of determinative judgment. An idea like “nature always follows the shortest path” may have an impact on our experience of nature, it may regulate that experience, but it does not come from the objects of nature.

  According to Kant, the apparently purposive nature of living things is another such idea. Because living things supplied their own purpose and did not receive it from outside themselves, the interaction of their parts involved a more complex causality than the linear causality of simple mechanisms. This because the parts and the whole of organism are bound together in such a way that, as Kant wrote in 1790, “they are mutually cause and effect of their form.”4 In organisms there is feedback among the parts: the heart pumps the blood that is needed by the heart to pump the blood. The usual kind of linear mechanical explanation that describes the motion of planets could not hope to capture the teleological nature of organisms.

  According to Kant, we can treat organisms as if they were being guided by special purposive forces, but when we do so such forces result from regulative, not constituent judgments like those at work in the causal explanations of physics. Hence we cannot say that such purposive forces actually exist, and there can never be a unified science that comprises both the physical and biological realms.

  There were a few fundamental implications of Kant’s view that would set the tone for philosophy of science in Germany for many years thereafter. First, Kant was essentially arguing that our use of reason in understanding the world stacks the deck, so to speak. For example, we cannot help but see things in three dimensions and in causal relationships. But this does not, in his view, mean that the world really exists in three dimensions or as causally connected. In the first edition of his famous Critique of Pure Reason of 1781 Kant wrote that “the understanding is not merely a capacity to give rules to itself by comparing appearances: it is itself the lawgiver for nature (Gesetzgebung für die Natur).”5 We apprehend the world for us, but we do not know what is like in itself (an sich). For many who came after him, Kant seemed to be saying that while we may be able to find regularities in nature that are useful to us, we can never discover the real truth of nature.

  Another important component of the Kantian legacy was his understanding of what he called genuine (eigentliche) science. Disciplines like chemistry and natural history, which could not be expressed through mathematically expressed mechanical laws, were categorized as merely empirical, not genuine sciences. As we have already noted, there could also be no genuine science of biology.

  17.3 FRIEDRICH WILHELM JOSEPH SCHELLING AND NATURPHILOSOPHIE

  This fracturing of our knowledge of the natural world into accessible and inaccessible realms and the glorification of causal-mechanical Newtonian science was unacceptable to the young Friedrich Wilhelm Joseph Schelling (1775–1854). Reared on Kant’s thought, Schelling concluded that his predecessor had made a fundamental error: he had assumed that the natural world must be regarded as mechanism when it should be seen as organism. This was perhaps due to Kant’s depicting the world from the vantage point of someone standing outside it. For Schelling organism was primary, mechanism secondary, and we know living things because we are living things.6 Our knowledge of living things is not confined to the laws of cause and effect that merely describe.

  Schelling set out to construct a view of nature that not only reflected nature’s organic essence but also healed the breach Kant had erected between things-in-themselves and things as we know them. This broad program for his understanding of nature became known as nature philosophy (Naturphilosophie) and it held that nature was an organized whole that could be understood by human reason. To understand the whole one had to acknowledge that nature as organism possessed qualities beyond the merely physical. Nature was imbued with moral and aesthetic dimensions as well. This of course meant that natural philosophers would have to broaden the vision of their enterprise, something that some did not wish to do.

  As a consequence of the broad systematic approach Schelling took to natural science he has often been understood, in his own day as well as in later years, to have spurned the empirical side of natural science in favor of deducing its principles transcendentally. In fact Schelling revered the empirical investigation of nature. In an introduction to a sketch of his system of nature philosophy from 1799 he made clear his awareness of the need for empirical verification that everything in nature was necessary. One counterexample, he said, was sufficient to destroy this assertion. He corrected the misunderstanding of some that nature philosophy was a purely deductive, armchair enterprise and in the process revealed his debt to Kant even as he attempted to move beyond him:

  The assertion that natural science must be able to deduce all its principles a priori is in a measure understood to mean that natural science must dispense with all experience, and, without any intervention of experience, be able to spin all its principles out of itself, an affirmation so absurd that the very objections to it deserve pity. Not only do we know this or that through experience, but we originally know nothing at all except through experience, and by means of experience, and in this sense the whole of our knowledge consists of the data of experience.7

  Schelling’s statement here brings into focus a central problem in philosophy of science with which German thinkers would struggle throughout the century, the problem of induction. Once the data of experience have been gathered, how does the natural philosopher then proceed to gather them together into a law of nature and what is the status of such laws? Schelling declared that the data can become principles, even a priori principles, but he did not tell us exactly how they are to be formulated. He merely says that the principles are justified by our consciousness of them as necessary. At other points he refers to a capacity of the human mind, intellectual intuition, as the means by which our awareness of them as necessary is achieved. Intellectual intuition also bridges the gap Kant had created between our knowledge of things and things in themselves.

  Kant had, of course, also appealed to the necessity of the results of his critique of reason, but for him intuition always had reference to objects of the senses; hence he specifically rejected the possibility of an intellectual intuition. By restricting intuition to the realm of the senses, Kant saw no way in which we could ascend from our knowledge of things to things as they are in themselves. But, other than noting the limitations of induction, he never specifically developed the challenge induction posed for the philosopher of science.

  17.4 JAKOB FRIEDRICH FRIES’S EXTENSION OF KANT

  Schelling’s embrace of intellectual intuition was also anathema to the neo-Kantian philosopher Jakob Friedrich Fries (1773–1843). Fries was initially drawn to Schelling as someone who, as he put it, was among the first to attempt to link philosophy of nature to the experimental sciences, a task he saw wanting in Kant. He eventually became a critic of Schelling and of Naturphilosophie, but early in his career he credited Schelling for insisting, in opposition to Kant, that all of nature must be regarded as a unified whole. As a consequence Fries took up the challenge of providing a corrective to Kant’s exclusion of organism from genuine science while remaining true to Kantian principles. He attempted to bring sciences like chemistry, for Kant a merely empirical science, into the fold of genuine sciences by developing a stoichiometric analysis of chemical force. His attempt to develop chemistry as a mechanical science failed, as did all efforts at the time to base chemical science on the mathematization of short-range chemical forces.8

  Fries also developed an elaborate new approach to organism that, unlike Schelling’s, kept it within the closed system of the material view of the world of external physics. To accomplish this he characterized organism in terms of cyclical motions
that could be described using the mathematical descriptions of Newtonian science. His attempt to create a mechanical system for chemistry and his philosophy of organism resonated among a few later German thinkers.9

  Fries recognized the importance of Schelling’s focus on induction and initially believed that Schelling had set out to illustrate and justify the role of induction in natural science. But he soon came to the conclusion that Schelling’s intent lay elsewhere and that his drawing of attention to induction was merely incidental. In his 1808 New Critique of Reason he explored for himself what was involved in a philosophy of induction because he had come to suspect there was a rational means through which the leading laws of natural science could be discovered. He did not abandon the Kantian conviction that the goal of a philosophy of nature lay in the grounding of mathematically expressed principles, thereby imparting necessity to them. But he did think that one might be able to arrive at, or as he said “divine” (erraten), such principles with the help of regulative means.10

  In pursuit of working all of this out Fries revealed his awareness of the challenge he had set for himself. It might be conceivable that one could identify what he called heuristic maxims that would enable one to divine general laws. But he did not say specifically how this was to be done. Already in a work of 1803 he made clear that with induction “fantasy is almost given free reign” and that in the hands of the unskilled things easily degenerate into frivolity.11 Fries here was lured by the prospect of spelling out exactly how induction, when done correctly, should proceed. At the same time he revealed some degree of awareness that such a prospect was unrealizable. His efforts did, however, influence students such as Ernst Apelt (see section 17.9) who focused explicitly on induction later in the century.

  17.5 CRITICS OF NATURPHILOSOPHIE

  Other opponents of Naturphilosophie in the early years of the century included those who preferred to emphasize natural science as the endeavor to find out how things work rather than as a philosophical system. Natural philosopher and anatomist Carl Rudolphi (1771–1832) complained bitterly about what he saw as Schelling’s flight into speculation, emphasizing that natural science prized careful observation above all else. While Rudolphi did not attempt to wrestle with the philosophical problems natural science raised, the same was not true of the botanist and chemist Heinrich Friedrich Link (1767–1850).

  Link challenged Schelling by attempting to claim Naturphilosophie for himself. From the outset of his work of 1806, Über Naturphilosophie, Link was careful to say that he was one for whom experience was the ultimate source of knowledge. But Link was no crass Baconian. He was clear about the limitations of empiricism and the necessary role of the subject in the acquisition of knowledge of the world. In particular he raised the problem of how exactly the natural philosopher unifies disparate sense observations into a unity. He was not content to solve this problem by resorting to Kant’s restrictive category of “genuine” science. But in the end, for all of his awareness of the thorny problems he had raised, the best he could do was to appeal to the “talent” of the individual to know how best to proceed, admitting in the process that natural philosophers were, as they were for Schelling, capable of exercising intellectual intuition.12

  17.6 JOHANN WOLFGANG VON GOETHE

  A critic of the Newtonian mechanical tradition was the novelist, poet, and playwright Johann Wolfgang von Goethe (1749–1832). Like Schelling, Goethe refused to accept that the sole and primary goal of natural science was to uncover the laws governing nature’s machinery. He too insisted that limiting natural science to the analysis of causal relationships among empirical phenomena was a mistake, although Goethe was not interested in creating a philosophical system like Schelling’s Naturphilosophie to correct it. That is not to say that Goethe was uninterested in the philosophical foundations of natural science. As we shall see, Goethe was more sensitive to the complexity of the philosophical issues science raised than most of his contemporaries. Goethe’s motivation, however, stemmed more from what he saw as the misplaced confidence natural scientists exhibited concerning what they were about. Once again, the challenge lay with what natural philosophers did with empirical observations.

  Goethe did not object to the scientist’s practice of uniting the facts of observation into a hypothesis. The creation of theories to explain causal relationships among empirical data is a worthy enterprise, but it must also be regarded as a necessarily one-sided representation of reality. This is because hypotheses necessarily emphasize one aspect of our sensual experience of the world, which by its nature is more unified. Arthur Zajonc quotes Goethe’s Maximen und Reflexionen13 to say that even our perception of the so-called facts of nature involves theorizing. It is the intellect that separates cause from effect and substance from its attributes.

  Goethe’s point here was two-fold. First, any hypothetical representation of nature, although it may be supremely useful, cannot give a true and final account of nature regardless of how much consensus is reached by the community of natural philosophers. Secondly, Goethe attempted to spell out that one can aspire to and even experience nature in its wholeness before causal theories are created to make nature useful to us.

  As a result of the first claim Goethe, in a much discussed and later maligned work, rejected Newton’s identification of color with the quantitative measure of its refrangibility. Newton may have begun by considering his account of color as a theory, but, as Goethe is quoted by Zajonc to say in his 1793 essay, “Newton’s Hypothesis of Diverse Refrangibility”: “By and by he binds himself so in spirit to his doctrine that he gives out diverse refrangibility as an actual fact.”14 More importantly, in the process of critiquing Newton, Goethe expounded his understanding of experiment as a mediator of nature. An experiment is not done to test an hypothesis, but to interrogate nature, to enable the researcher to help the object provide its own meaning rather than to use the object to reinforce the opinion a researcher already has. Goethe summarized these ideas in the notion of a Vorstellungsart, or way of thinking. In our observations of nature we employ differing ways of thinking, as the result of which we can never be neutral observers of the nature. As he put it, with every attentive look at the world we are already theorizing. Further, as Dennis Sepper’s analysis makes clear, because the world as experienced is plural, no one way of thinking is sufficient and none, Newton’s or anyone’s, should become exclusive.15 This dimension of Goethe’s philosophy of science found more resonance in the twentieth century than it did in his own.

  Goethe’s second point, that one can aspire to and even experience nature in its wholeness, was related to his first. To do this one begins with ordinary observations of sense that every natural philosopher might make, including the notation of the conditions that affect its appearance. The next step, which not everyone can do, is to train the mind to seek regularities of the most general kind. To do this Goethe says in 1798 that the intellect must learn how to fix what is variable to the senses, to exclude what is accidental, to separate what is impure, to unravel what is jumbled, and even to discover what is not yet known.16 Goethe here seeks the archetypal phenomenon, nature at its purest for humans. His pursuit of this goal contributed to his discovery of the intermaxillary bone, at the time thought to be present only in mammals, reptiles, and amphibians, in humans.

  17.7 PHILOSOPHY OF ORGANISM AND THE QUESTION OF VITAL FORCE

  An early devotee of the approaches of Schelling and Goethe was the physiologist Johannes Müller (1801–58), who would become famous as much for the students he taught as for the original scientific results he produced. As he studied for two years in the early 1820s under the tutelage of Carl Rudolphi in Berlin, Müller became dissatisfied with Schelling’s escape into intellectual intuition to explain the correspondence between thought and the real world. But, unlike Rudolphi, Müller did not disparage philosophy.

  Müller rejected what he called “rational physiology” (verständige Physiologie), by which he meant physiology as Kant would depict i
t. He shared with the romantics the conviction that the Kantian breech between the phenomenal and noumenal realms was unacceptable. But having discarded Schelling’s intellectual intuition, Müller faced the challenge of overcoming Kant’s restriction of reason in some other manner. Even Goethe’s artistic induction could not help since Goethe conceded the existence of an unbridgeable cleft between experience and idea.

  Müller became famous in the 1830s for his law of specific nerve energies, according to which the different sensations we have—seeing, hearing, and so on—are not caused by differences in the stimuli but by the different nerves that are excited. For example, regardless of how nerves of the eye are stimulated—by pressure, electricity, and so on—we experience flashes of light. This result only made Müller’s philosophical challenge more difficult since there was no longer a one-to one correspondence between a particular stimulus and the resulting sensation. How are we then to fashion a correlation between what we experience of the world and the world as it is in itself?

  Some took this development as support for Kant’s viewpoint. Müller conceded that the result implied that the real nature of things remains unknown to us, but insisted that there was a fixed relation between things and our ideas so that our sensations can be used as true signs of things. Ultimately we do not sense objects; rather, we sense us ourselves. In place of intellectual intuition as a way of knowing that we have uncovered the true relation between ideas and the signs of things we experience Müller appealed early on in 1824 to “an organ of a higher kind,” later, in his Handbook of Physiology, to the capacity of abstraction to make “an entity of thought out of what is common to many recurring linkages between two things [true ideas and the signs of sense experience], each of which requires the other.”17 In spite of his insistence on careful empirical work, a conviction he learned from Rudolphi, Müller’s appeal to abstraction marks him, in the end, as closer to Schelling’s intellectual intuition than Kant’s restriction of scientific explanation to the phenomenal realm.