Beiser's Neo Kantians (7): Zeller
Eduard Zeller appears in Beiser’s story as the quiet, methodical figure who shows that neo Kantianism can be serious and sober rather than dramatic. Where someone like Kuno Fischer turns Kant into a stage play about freedom and will, Zeller turns Kant into a discipline, almost a temperament. For Beiser, he is one of the central figures of the 1860s revival, the decade when “back to Kant” becomes an academic programme rather than a slogan, and when philosophy starts to redefine itself as theory of knowledge. Zeller begins life deep inside another tradition. He is trained as a Protestant theologian in the Tübingen school, under the influence of Hegel. His early work is in theology and his great scholarly monument is the multi volume Philosophy of the Greeks, the standard nineteenth century history of Greek philosophy.
That big history is important for Beiser because it shows the kind of thinker Zeller is. He is not a system builder with a single brilliant idea. He is a slow, careful reader, a historian who traces how concepts arise and change. When he later turns “back to Kant”, that historical discipline shapes how he understands what critique can be. Beiser points out that Zeller’s road from Hegel to Kant runs through Marburg. He first takes a chair in theology there, then after conflict with conservative clergy shifts into philosophy. Marburg is where he develops the habits that will mark his neo Kantian phase. His work on Greek philosophy forces him to distinguish content from form. The historical content is contingent and varied, while the logical forms by which it is organised are not the same thing as that content. A logical pattern cannot simply dictate what a historical sequence must be. This lesson, Beiser says, lies behind Zeller’s later refusal to let logic turn into metaphysics in the Hegelian way.
When Zeller moves to Heidelberg in 1862, he gives an inaugural lecture that Beiser treats as a milestone in the Kant revival. The lecture is called something like “On the Meaning and Task of the Theory of Knowledge”. That title already signals the change. Instead of talking about “metaphysics” or “the system of philosophy”, Zeller talks about Erkenntnistheorie, theory of knowledge, as a distinct discipline and as the central task for philosophy. He argues that philosophy stands at a turning point. The great idealist systems have broken down and cannot be patched up. If philosophy tries to continue in that style, it will simply be ignored by the sciences and by educated opinion. Zeller’s proposed remedy, as Beiser reconstructs it, is simple and radical. Philosophy must make epistemology first philosophy. That means it must ask, before anything else, how knowledge is possible and what the limits of knowledge are. Only after that can it do metaphysics, ethics, or religion in a responsible way. Logic, on this view, is not the study of being. It is the study of the forms of judgement and inference we use to know things. Metaphysics, like any special science, presupposes those forms and methods. So epistemology, not metaphysics, has the right to call itself “fundamental”.
Imagine a group of children arguing about a game. Some talk about what the pieces are, how strong they are, how they move. One child says, “Before we go further, we have to agree on the rules of the game, otherwise none of this will make sense.” That child is doing something like what Zeller wants philosophy to do. The rules are not about the colour of the pieces. They are about how moves count, what it means to win, what counts as a fair move. For Zeller, epistemology is the investigation of the “rules” of knowing, and philosophy should start there. This shift is part of what Beiser calls the “priority of epistemology” in early neo Kantianism. Fischer and Zeller together turn Kant into the philosopher of knowledge for a generation. Fischer does it through dramatic lectures and bold interpretations. Zeller does it through a more austere, historically grounded argument that we must go back to the step where Kant put theory of knowledge at the centre.
At the heart of Zeller’s Kantianism, as Beiser tells it, lies a respect for dualisms. Kant had insisted on certain basic distinctions: between sensibility and understanding, between form and matter, between knowing and being, between phenomena and things in themselves. Hegel’s dialectic had tried to overcome these splits, to dissolve them into a higher unity where thinking and being are the same. Zeller slowly comes to think that this Hegelian ambition is a mistake. The very power of Kant’s critical philosophy lies in the way it keeps some contrasts in place. In Marburg and Heidelberg, Zeller argues that philosophy must keep distinct the order of knowing and the order of being. We should not assume that because our thoughts are structured in a certain way, reality must be structured in exactly the same way. Logic, he says, is formal. It is about the forms of our judgements, not about the true structure of things. This is a direct rebuke to Hegel’s idea that logic can be a kind of “metaphysics”, reading the nature of reality off the structure of the concept. Zeller insists that the forms of thought are tools for knowing. They do not, by themselves, generate content. Another Kantian dualism he defends is the split between norm and fact, validity and existence. When we say that a belief is justified, or that a law of nature holds, or that a value is binding, we are not just describing how things happen to stand. We are making a claim about what ought to be accepted or followed. Zeller uses this to fend off crude materialism. Materialists in the 1850s and 1860s liked to argue that because science has shown how things are, ethics and religion are illusions. Zeller’s answer is that the “is” does not settle the “ought”. Facts about brain processes or about causal laws do not directly tell us which beliefs are justified or which actions are right. That distinction between validity and existence, which Beiser highlights, will later become a central theme in the Baden school as well.
Beiser spends a good deal of time on Zeller’s position in the Fischer–Trendelenburg dispute, because it reveals exactly what kind of neo Kantian Zeller is. The dispute centres on Kant’s arguments in the Transcendental Aesthetic, the part of the Critique of Pure Reason where Kant claims that space and time are forms of sensibility, features of how we perceive, not properties of things in themselves. Fischer reads Kant as saying that space and time are purely subjective, and he uses this to build a strong divide between appearances and things in themselves. Trendelenburg objects that Kant’s arguments do not actually exclude a third possibility, namely that space and time are both forms of our intuition and also in some way correspond to the structure of things as they are in themselves.
Zeller sides with Trendelenburg on this point. Beiser notes that in his Heidelberg lecture Zeller criticises Kant’s claim that things in themselves are strictly unknowable. Zeller thinks there is a non sequitur here. From the fact that our forms of knowledge, such as space, time and the categories, arise from us, it does not follow that they fail to correspond to things as they are. It may well be that the very forms through which we know are the way things in themselves are structured. Zeller calls this a kind of transcendental realism, meaning that he identifies the objects of our experience with reality itself, not just with mere shadows of it.
Kant is often read as saying something like: we always look through blue tinted glasses, so we can never know whether things are really blue or not. Zeller says, in effect: maybe the glasses are blue, but it might still be true that the world really has blue features. Just because the tint is contributed by us, it does not follow that the tint does not match the world. This is his “third possibility” which Fischer’s more rigid reading tended to exclude. Zeller’s realism appears again when he talks about sensation. Kant had treated sensations as the “matter” of experience, given from outside, which are then structured by a priori forms. Zeller argues that the determinate spatial and temporal relations among things cannot be simply imposed by our forms. They are also given. He believes at first that within experience we really can know things in themselves, because the coherence of our experiences and their conformity to scientific laws give us sufficient criteria for reality. We do not need to step outside representation to check.
Beiser then shows how Zeller’s position shifts under the influence of new science. In later reflections, about fifteen years after the Heidelberg lecture, Zeller encounters the work of Müller and Helmholtz on the physiology of the senses. These experiments show that the quality of sensation depends strongly on the properties of nerves and brain, not just on the external stimulus. That means that representation will not resemble its cause in any simple way. With this in mind, Zeller extends the “a priori” to sensation itself. The content of our sensations is shaped by our sensory apparatus in a deeper sense than he had allowed. Once he accepts that, he can no longer maintain that our representations mirror things in themselves. We are thrown back into something much closer to Kant’s own cautious view: we know only appearances, things as they affect us, and the thing in itself remains a limit concept that we cannot fill with content.
This development matters for Beiser’s overall story because it shows Zeller working through the same tension that runs through the whole neo Kantian movement: the pull toward realism, the wish to say that science tells us about reality itself, and the pull toward critical idealism, the insistence that our knowledge is always shaped by our own forms. Zeller tries at first to lean more toward realism, then is pushed back by physiological psychology toward a stricter critical stance. He ends up, with Lange and Liebmann, conceding that the thing in itself is ineliminable as a limit thought, even if we can never know it.
Another place where Beiser highlights Zeller’s sobriety is teleology, the use of talk about ends and purposes. Zeller is perfectly at home reading Aristotle, for whom teleological language is natural. Organs exist for the sake of the whole, species have natures that aim at certain forms of life, and so on. But when it comes to modern philosophy of nature, he insists that purposive language must be disciplined by Kant’s idea of reflective judgement. In practical terms, that means we can use purposiveness as a way of organising inquiry, especially in biology and history, without turning it into bold claims about the inner nature of reality. To say “this organism is as if arranged for a purpose” helps us see connections. It does not entitle us to say “nature itself is governed by purposes in itself.” He sounds like Dan Dennett.
Here Zeller parts company with Fischer, who, as Beiser shows, likes to turn the “as if” into an “is”, interpreting Kant’s purposiveness as revealing will as the inner essence of both nature and morality. Zeller will have none of this. For him, the line between regulative principles, which guide our thinking, and constitutive claims, which state what reality is like, must be kept clear. Teleology belongs on the regulative side. That is another example of his attachment to Kantian dualisms: he wants to keep the tools of judgement and the structure of reality conceptually distinct, even if they are in practice in harmony. Beiser’s portrait of Zeller also stresses his role as a public figure, not because he was a flamboyant personality, he was not, but because he modelled a particular philosophical attitude. In Berlin from 1872, he becomes an elder statesman of critical thought. Students remember his method more than any single doctrine. He would take a famous thesis, often from the history of philosophy, strip away its legends, reconstruct the steps that had once made it plausible, and then show the range of cases where it still illuminates and where it no longer does. That way of working is itself Kantian. It takes seriously the idea that philosophy is second order, that it examines our ways of thinking rather than jumping ahead of them.
Beiser draws a useful contrast between Fischer and Zeller that helps fix Zeller’s place. Both had been formed in the school of Hegel and Strauss. Both turn to Kant to save philosophy from obsolescence in the face of the sciences. Both want to protect religion from speculative appropriation and from crude materialism. Fischer, however, never stops longing for a single metaphysical centre. He wants to unify nature and freedom under the idea of will. Zeller, by contrast, accepts the discipline of plurality. He prefers an architectonic of standpoints to a doctrine of one substance. He is willing to leave some gaps unbridged if bridging them would cost the very distinctions that make objectivity possible. This is why Beiser describes Zeller’s legacy as methodological and even moral. Zeller does not give later neo Kantians a grand new doctrine. He gives them lessons in how to proceed. Do not let a taste for system outrun the evidence. Do not confuse questions of fact with questions of right, that is, do not let what happens in nature or in society decide what counts as valid knowledge or just action. Do not mistake the success of the natural sciences for a licence to forget critique. These are modest sounding maxims, but they set the tone for what Marburg and the Baden school will later do in more specialised ways.
From a broader angle, Zeller helps Beiser explain how neo Kantianism emerges not as a sudden new ideology but as the result of a series of adjustments. Early figures like Fries and Herbart had already said that philosophy should become critical and should respect the sciences. They still thought one could use psychology as the basic route into that project. Fischer then made Kant vivid and exciting again, but at the cost of blurring the line between critique and metaphysics. Zeller tightens things up. He recommends epistemology as the central task, insists on the key dualisms, resists both speculative idealism and positivism, and shapes a generation of historians and philosophers who learn to treat concepts as objects of investigation.
Think of a referee who insists that before you play any game you really need to read the rule book and keep it separate from the excitement of play. That is Zeller insisting on the priority of epistemology. Think of a judge who keeps reminding everyone that what the law says and what people actually do are not the same thing. That is Zeller insisting on the distinction between validity and existence, between norm and fact. Think of a careful map maker who refuses to say that the grid lines on a map are literally painted onto the landscape, but who also refuses to say that they are mere fictions unrelated to anything real. That is Zeller wrestling with the forms of intuition and the thing in itself, allowing a realist reading but finally accepting that there is a limit to what we can know.
In Beiser’s narrative of the genesis of neo Kantianism, Eduard Zeller stands as one of the key figures of the 1860s, the formative decade. His role is not dramatic, but it is decisive. He shows that “back to Kant” can mean a disciplined theory of knowledge, historically informed and scientifically aware, rather than a new metaphysics in disguise. Later schools, whether they focus on the logic of science or on value and culture, inherit his caution. They try, each in their own way, to keep the gains of criticism that Zeller worked so hard to protect, while exploring new territories that he helped to open.