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AGPh 2023; aop
Elisabeth Widmer*
‘Left-Kantianism’ and the ‘Scientific Dispute’
between Rudolf Stammler and Hermann
Cohen
https://doi.org/10.1515/agph-2021-0181
Abstract: This paper argues that the ‘scientific dispute’ between Hermann Cohen
and Rudolf Stammler is symptomatic of a philosophical movement of left-wing Kant
interpretations at the turn of the twentieth century. By outlining influential prede-
cessors that shaped Cohen’s and Stammler’s thinking, I show that their Kantian
justifications of socialism differ regarding their conception of law, history, and the
political implications that follow from their practical philosophies. Against scholars
who suggest that the Marburg School’s view on socialism was a coherent school of
thought, I introduce the concept of ‘left-Kantianism’ as an open term that includes
a wide variety of novel socialist approaches to Kant at the time.
Keywords: Socialism, Post-Marxism, Marburg School, Neo-Kantianism, Hermann
Cohen, Rudolf Stammler, Friedrich Albert Lange, Adolf Trendelenburg, Friedrich
von Savigny, Scientific Dispute, Left-Kantianism.
1 Introduction
While in recent years interest in the neo-Kantian Marburg School has increased,
research focusing on their legal and political philosophies is still rare. In cases
where scholars do discuss the political side, we find the view that the proponents
of the Marburg School defended a coherent view of ethical socialism. Thomas
E.Willey argues that “Marburg neo-Kantian Socialism” was a “coherent intellec-
tual movement” just before the First World War (Willey 1978, 116). Similarly, Fred-
erick Beiser subsumes Rudolf Stammler, Franz Staudinger, Karl Vorländer, and
Kurt Eisner under the umbrella term of “ethical socialism” without noticing that
Stammler explicitly refrained from advancing an ethical foundation (cf. Beiser
2018, 2). However, this view does not correspond to the self-conception of the
School’s members. Paul Natorp (1854–1924) thought that the differences between
*Corresponding author: Dr.Elisabeth Widmer, Postdoc, IFIKK, University of Oslo, Norway;
e.t.widmer@ifikk.uio.no. https://orcid.org/0000-0002-8939-0978
2023
Open Access. © 2023 the author(s), published by De Gruyter. This work is licensed under the
Creative Commons Attribution 4.0 International License.
2 Elisabeth Widmer
Hermann Cohen (1842–1918) and Rudolf Stammler (1856–1938) were so severe that
he devoted an article to what he called their “scientific dispute” (Natorp 1913).
The Marburg School evolved during the peak of ‘historicism,’ a current con-
cerned with the historicization of the conditions of knowledge. The neo-Kantian
Marburg School’s ‘critical idealism’ seemed to counteract these developments. The
most famous of its members, Cohen and Natorp, agreed on a Kantian a priori and
ideal foundation of truth and morality. At the same time, however, they tried “to
overcome the dualism between intuition and thinking and between matter and
form” (Natorp 1986/1911, 65). They thought that rational thinking manifests teleolog-
ically. Instead of justifying definite a priori principles, they took scientific concepts
and cultural norms as expressions of rationality, striving toward the unification of
thought and belief systems. With their teleological approach to Kantian idealism,
they were in line with the general trend of historicizing scientific knowledge and
social norms.
Moreover, the School evolved during the “golden age of Marxism” (Kolakowski
1988, 11). Prussia was dealing with the consequences of the growth of industrializa-
tion and the crises of capitalism. The so-called worker’s question—the question of
whether and how the situation of the workers could be improved—was a widely
discussed topic among progressive, left, and conservative intellectuals alike. Right-
wing conservative neo-Kantians, such as Jürgen Bona Meyer and Hermann von
Helmholtz, believed that socialism was responsible for the allegedly moral and
societal downfall of the late 1870s (Sieg 2013, 38–39). In contrast, the representatives
of the Marburg School were convinced that an actualization of Kantian philosophy
would lead to a justification of socialism. With a sensitivity to the historical nexus,
the members of the school drew on Kant’s transcendental critique to work out a
methodology that could engage with the inconsistencies of capitalism.
With their novel teleological approaches to Kant, new questions arose: How is
it possible, on the one hand, to historicize social norms and, on the other, to uphold
a normative and ideal foundation allowing for political critique? What is the sys-
tematic foundation for normative critique? How can we promote societal progress?
And what practical implications might follow from this?
This paper aims to show that the answers to these questions offered by the
proponents of the Marburg School diverged in a number of crucial, if not irrecon-
cilable, respects. More specifically, I seek to identify two ways of justifying social-
ism within the Marburg School in light of the “scientific dispute” (Natorp 1913, 1).
1Historicism is typically divided into a ‘positivist’ strand, characterized by a value-free attitude
towards empirical facts of history, and a ‘relativist’ strand, characterized by active resistance
against absolute claims about truth and morality (Schnädelbach 1983, 51).
‘Left-Kantianism’ and the ‘Scientific Dispute’ 3
Cohen defended an adapted version of Kant’s moral law as a universal principle of
culture that allows one to criticize capitalist norms from an ethical point of view.
Rudolf Stammler (1856–1938) provided a transcendental justification of law sepa-
rated from morality, arguing that the inconsistencies between the legal system and
economic conditions provided the normative foundation for political criticism.
I shall argue that Cohen and Stammler approached their Kantian foundation
of socialism from very different backgrounds. Although they were both inspired by
Friedrich Albert Lange’s views on socialism and sought to overcome a Darwinist
justification of the ‘worker’s question,’ Cohen and Stammler worked out two funda-
mentally different theories of Kantian socialism. Cohen’s approach was inspired by
the natural law tradition, especially the version proffered by the ArIstotelian Adolf
Trendelenburg. Stammler, however, considered class struggles to be the result of
an ‘outdated’ legal system regulating the economic sphere, thereby providing a
critical-idealist alternative inspired by Friedrich von Savigny’s ‘Historical School.’
In highlighting these differences, I suggest letting go of the descriptors ‘Marburg
neo-Kantian socialism’ or ‘ethical socialism,’ which mistakenly imply a coherent
foundation of socialism. Instead, I argue that these two approaches were part of a
broader philosophical current in the Kantian tradition that includes various left-
wing justifications of socialism beyond the Marburg School.
The paper is divided into six sections. In the second section, I highlight the
fundamental differences regarding the demarcation between law and morality in
Trendelenburg and Savigny. In the third section, I show that the first neo-Kantian
socialist, Lange, provided an aesthetic account of natural law that grounds his his-
toricist view on social norms. In section four, I discuss Cohen’s left-Kantian revival
of the natural law tradition, which is conceptualized with Trendelenburg’s natural
law and Lange’s critical idealism in mind. In the fifth section, I address Stammler’s
left-Kantianism and show that he critically draws on Savigny and Lange’s histori-
cist view. In the sixth section, I establish how Cohen and Stammler differ regarding
methodology, history, and the practical implications that follow from their respec-
tive accounts, arguing that these positions are characteristic of a broader current
I call ‘left-Kantianism.’ The paper concludes with a summary of the main findings
and a view to potential avenues for further research.
2 Important Predecessors: Adolf Trendelenburg
and Friedrich von Savigny
Three philosophical positions are hovering in the background of the ‘scientific
dispute.’ The natural law theory of Adolf Trendelenburg (1802–1872), the historicist
4 Elisabeth Widmer
approach of the ‘Historical School’ of Friedrich von Savigny (1779–1861), and—as I
will discuss in the next section—the early neo-Kantian socialism of Friedrich Albert
Lange (1828–1875). Due to a lack of space, I will not discuss their theories in full.
Instead, I will focus on those aspects that are later reflected in the works of Cohen
and Stammler.
Trendelenburg had a major influence on natural law theory in the nineteenth
century. Natural law theory in this context signifies the idea that juridical practice
or legal judgments are ultimately grounded on a principle of justice that is innate to
human nature or rationality. Trendelenburg was influenced by Aristotle and Kant.
He offered an interpretation of the categories of time and space as being both ideal
and real at the same time—a position that evoked the famous Trendelenburg-Fis-
cher debate. In his practical philosophy, Trendelenburg defended a historically
embedded view of practical rationality materialized in a “concrete” conception of
the Kantian notion of universality, grounding the basis for his natural law theory
(Brüllmann 2019, 207).
To understand Trendelenburg’s historically embedded concept of natural law,
we first need to look at his logical and epistemological framework. In Logische
Untersuchungen (1870), Trendelenburg “reforms” the logical foundation in natural
philosophy (Hartung 2019, 79–83). He agrees with Hegel that rationality is a histor-
ical practice. However, he adds that Hegel’s dialectical logic fails to account for a
crucial presupposition: “spatial movement” (Trendelenburg 1870, 42).
Trendelenburg illustrates the problem of “spatial movement” with the follow-
ing example: “While the day is coming, it is already, and it is not yet” (1870, 38). Log-
ically, this sentence violates the law of identity—namely that A and not-A cannot
both be true at the same time. However, the problem is presented differently if we
include the human being’s ability to perceive the object in its transitional mode of
existence. From an Aristotle-inspired and ontological point of view, Trendelenburg
argues that “contradictions” are “based on receptive intuitions,” meaning that pure
thinking would rely on an intuitive category of coming-into-being (1870, 56). If we
include the category of coming-into-being, we can ascribe A and not-A ontologically
to an object, holding A and not-A to be true at the same time. Call this the ‘principle
of continuity.’
2Scholars have dealt differently with Trendelenburg’s aesthetic categories. Graham Bird has
argued that Trendelenburg confused the objective and subjective categories in Kant (Bird 2006).
Edward Kanterian has contested this view, arguing that Trendelenburg’s program included a cri-
tique of Kantian transcendentalism that leaves us with a more nuanced and less ambiguous under-
standing of time and space (Kanterian 2013).
3Politically, Trendelenburg was a “loyal Prussian who believed that the Hohenzollers [the ruling
German aristocracy] were the very model of enlightened rule” (Beiser 2013, 71).
‘Left-Kantianism’ and the ‘Scientific Dispute’ 5
Trendelenburg uses the principle of continuity to reformulate an account of
historical reason. In his view, it is the philosopher’s task to “recognize the objects
of knowledge that find their origin […] in the a priori conditions” (Trendelnburg
1870, 236). Methodologically, this requires the identification of concepts and norms
that were initially generated by reason. “[A]s the spirit opens its senses, […t]he a
priori principle of freedom is found in its movement [Bewegung] in physical objects
and ethical norms” (Trendelnburg 1870, 237). Freedom is not only an abstract idea
but finds its materialization in objects and norms constituting the facts of history.
Just as the category of coming-into-being allows us to ascribe both A and not-A to
the same object, so the category of coming-into-being allows us to perceive facts of
history as determined and caused by a free will.
Against this background, the principle of continuity reappears in Naturrecht
auf dem Grunde der Ethik (1868). Trendelenburg criticizes approaches in which an
ideal principle of justice is taken as a “last foundation” (letzter Ursprung) without
considering its appearance. Convinced that philosophy must “screen history
regarding its [rational] origin” (1868, 5), he claims that the principle of justice “must
be found in its historical formation” (1868, xi). Trendelenburg remains ‘Kantian’ as
he holds onto a logical and a priori understanding of the notion of ethical freedom
that guides our focus on the historical instantiations of positive laws. In this sense,
he retains the distinction between the ideal and the empirical notion of morality,
arguing that we must judge legal norms by their underlying focus. “In contrast to
the changing particular [Besondere] of the many wills, which dresses in the major-
ity of votes only appearing to be universal, we demand the universality [Allge-
meine] as the essence of reason that underlies juridical judgments” (1868, 16). While
all juridical norms are objects of experience, Trendelenburg aims to disentangle
juridical laws entailing a notion of ethical universality that is distinct from norms
of convention. The ‘organic worldview’—as Trendelenburg calls it—allows for a
continuous view of the normative and ethical origins underlying substantive ideas
in history. While in the theoretical sphere the principle of continuity builds on the
category of ‘spatial movement,’ in the practical sphere the principle explains how
a set of norms can be substantiated and grounded by a free rational will under the
category of an ‘ethical end.’
By ethicizing the legal sphere (Hartung 2008, 297), Trendelenburg faces a novel
problem. In Kant’s view, the legal and the moral realms ideally coincide. However,
systematically, they target different norms. In the moral sphere, we deal with inter-
nal and autonomous laws, while in the legal sphere, we deal with external and coer-
cive laws. But if all empirical social standards—including juridical models—are
measured by an underlying ethical end, how is it possible to uphold this distinction?
Trendelenburg answers as follows: “The merit of this [Kant’s] legal concept lies
in its generality [Allgemeinheit] but its defect in the generality conceived only exter-
6 Elisabeth Widmer
nally” (1868/1860, 16). Since Trendelenburg considers all social norms as “ethical
germs” measured by their “ethical end,” he rejects the Kantian systematic differ-
entiation between legality and morality, where the former is based on “external
means” of “coercion” (1868/1860, 12). Instead, he argues that legal norms—material-
ized in the social realm—are measured by their ethical end.
An entirely different view on juridical laws is painted in Vom Beruf unserer
Zeit für Gesetzgebung und Rechtswissenschaft (1814) by Savigny. In contrast to the
natural law tradition, Savigny rejects the idea of an innate rational principle of
justice guiding our legal practices. As Reutter aptly puts it, for Savigny, “being” is
“positive law” or the “concrete legal being” (2011, 75). Methodologically, Savigny
argues that the legal sciences (Rechtswissenschaft) need to restrict their investiga-
tion to inductive investigations of historically formed legal contents.
Savigny’s methodology is restricted to the causal investigation of substantive
norms or positive laws in their empirical appearance. What counts as ‘just’ cannot
be answered on the basis of an ideal principle underlying historical judgments.
Instead, justice can only be measured by the standards of the period within which
such judgments emerged. While Trendelenburg argues that it is possible to rec-
ognize different sets of legal norms over time with respect to their ethical basis,
Savigny criticizes such approaches for their “bottomless idleness” in assuming
an ideal foundation “standing up and above” human practices (1814, 6). The legal
sciences’ task is to investigate the “substantial formation” of legal systems and
define the most characteristic traits of a certain period (1814, 6). In contrast to the
natural law camp, which emphasizes the rational continuity in legal judgments,
Savigny’s framework focuses on the contingent aspects of legal norms, saying that
general claims are based on recognizing the changing character traits of different
sets of legal norms over time.
Savigny does not refrain entirely from normative assertions; however, he
grounds his view on a psychological theory of the Volksgeist. According to Savigny,
investigating the individual character traits of legal systems means identifying the
psychological principles of a society that ground the epistemic conditions of reality.
This allows for inferences to be made about the stage of the “consciousness of the
people” (Bewußtsein des Volkes) (1814, 9). What follows from studying historical
legal textbooks is the identification of “general characterizations of a period” (1814,
9). Savigny differentiates between arbitrary moral and religious convictions, which
develop “naturally” in society, and “objective” laws we intentionally institutional-
ize in order to regulate social behavior. Law does not evolve in a vacuum; it is the
institutionalization of what we consider right (1814, 13). Savigny thus claims that the
“only true and natural law is the one understood in relation and interaction to the
general [political] culture” (1814, 48). Undertaking historical comparisons enables
one to identify and contrast character traits of “primitive” and “higher” legal cul-
‘Left-Kantianism’ and the ‘Scientific Dispute’ 7
tures. The normative principle based on which Savigny distinguishes between
“primitive” and “higher” legal cultures is of a linguistic nature; the more abstract
and formal the (legal) language of a culture is, the more cultivated society is.
This method is illustrated in his analysis of modern civil law. While civil law
was characterized by “symbolic deeds” in earlier stages of humanity, modern civil
law was marked by more “formal” language and behavior (1814, 10). Savigny claims
that modern law would presuppose a level of linguistic abstraction similar to that
of ancient Roman law. This example illustrates what Savigny is after methodolog-
ically: “We try to present general features of a period in which law, like language,
lives in the consciousness of the people” (1814, 9). Thus, the analysis of language,
focusing on the level of formality, is taken as a criterion based on which “general”
statements about the cognitive stage of a “Volk” become possible (1814, 23).
Trendelenburg and Savigny both aimed to historicize knowledge, and, in this
sense, they were part of a tradition reacting to ahistorical forms of idealism. Yet,
their reactions to ahistorical idealism differed. Savigny’s theory does not allow
for a context-free evaluation of norms. Social norms are merely depicted in their
coercive, empirical, and external manner. Legal and moral norms are institution-
alized (objective) reflections of a specific period. Trendelenburg seeks to identify
the ethical norms underlying legal judgments, thereby holding onto a continuous
and idealist view of norms by disentangling the universal element beneath empir-
ical laws. Moreover, they were representatives of differing disciplines and gener-
ations. Savigny was 23 years Trendelenburg’s senior and—with Gustav von Hugo
(1764–1844)—a founding figure of the Historical School of Jurisprudence (Histor-
ische Rechtsschule) that consisted almost exclusively of jurists. Trendelenburg, in
contrast, was a philosopher and philologist who integrated historical developments
into his idealist system, which was highly influential in the debates on the method-
ology of the history of philosophy.
3 The First Neo-Kantian Socialist: Friedrich Albert
Lange
Friedrich Albert Lange—sometimes called the “father of Marburg neo-Kantianism”
(Sieg 1994, 86)—was the first neo-Kantian philosopher to defend socialism. Accord-
4I do not translate Volk into ‘people’ because this concept is a technical concept that refers to a
collective body of knowledge commonly used in the nineteenth century to describe the state of a
society at a specific period in time.
8 Elisabeth Widmer
ing to Lange, class struggles are an effect of evolution. Adam Smith’s sensualist
account of moral sentiments, August Weismann’s adaptation of Darwinism, and
Thomas Malthus’ law of population are essential reference points that, in Lange’s
view, have helped to understand the capitalist ‘struggle for survival.’ However,
underlying Lange’s whole philosophy is a critique of materialism and naturalism,
arguing that such approaches leave the psychological and physiological condi-
tions of (social) experience unexplored. Influenced by Hermann von Helmholtz
(1821–1894) and Johannes Müller (1801–1858), Lange is convinced that materialism,
broadly conceived, paves the way for a naturalist interpretation of the conditions of
social experience. Understanding the conditions of social experience would mean
scrutinizing the origins of egoistic behavior with the means of statistics and psy-
chophysics (Lange 1870, 115–117). Lange did not provide an in-depth philosophical
study of legal norms. However, since his view on jurisdiction remained vague, it is
possible to situate him within both the natural law and the historicist traditions.
Let us first look at Lange’s account of aesthetics, which moves in a similar
direction to that of the natural law tradition. Lange is convinced that we can inves-
tigate the social realm like the natural realm with empirical-scientific methods due
to the subjective psychological categories of understanding. However, there is one
crucial difference between the social and the natural sciences. While in the realm
of nature, scientific practice is guided by a critical conception of the ‘thing-in-itself,’
the examination of the social domain presupposes an ethical ideal of “equality”
(Lange 1870, 266).
Driven by the aim of overcoming old metaphysics, Lange rejects the meta-
physical and logical implications of the idea of universality in Kant. Instead, he
argues that the notion of universality is an aesthetic fiction. “The same principle
that prevails in the realm of beauty, art, and poetry, prevails in the realm of action
as the true ethical norm” (Lange 2015/1866, 554/982, emphasis added). Instead of
rationalizing the concept of universality, Lange tackles the issue from a sensual-
ist foundation and differentiates between “primitive pleasure” and “more refined
sensual pleasure” (2015/1866, 509/905). The latter comprises the aesthetic joy felt
when we listen to the rhythm of a song or poem, enjoy a painting’s matching colors,
or imagine social norms in a coherent ethical order. By comparing the empirical
social norms with the “idea of equality,” we recognize unjust social structures that
conflict with our inner picture of a harmonious social order. “Only through this
contrast,” claims Lange, “reality appears evil” (2015/1866, 22). In Lange’s view, we
can differentiate between just and unjust norms due to our innate aesthetic incli-
nation to create a mental picture that deviates from the given reality.
Lange’s aesthetic account is reminiscent of the natural law tradition, as it argues
for an innate moral conception of justice as an ahistorical idea, which allows us to
criticize social norms. To Lange, the “idea of equality” functions as a critical concept.
‘Left-Kantianism’ and the ‘Scientific Dispute’ 9
Injustices of an unequal distribution of goods, the exploitation of workers, and the
mechanisms supporting capitalism are viewed and criticized from an ethical point
of view. Following this line of thought, socialism appears as a moral movement striv-
ing for legal reforms based on an aesthetic foundation of justice.
Alongside Lange’s aesthetic idealism, we find another line of argument that
will later inform Stammler’s naturalist focus on class struggles. More in line with
the historicist tradition, Lange bases his political philosophy, inspired by Smith, on
two opposite natural dispositions underlying class struggles: our inclination for
“sympathetic” behavior and our inclination for “egoistic” behavior. Class struggles
appear if structures promoting egoistic behavior are in place. Here, Lange takes
legality in its contingent appearance: “Between Spartans and Helots, […] between
lords and subservient, between the noble and rabble existed a moral law based
on class prejudices” (1866, 57). Lange builds on a relativist conception of legality,
suggesting that what counts as ‘right’ depends on a legal contract that makes a legal
norm just. “Even slavery or the payment of tribute to a robber can be regarded as a
contract that was once considered lawful” (1870/1865, 252). His relativist conception
of justice is also found in the Geschichte des Materialismus, where he states: “The
whole practical philosophy is the changing and variable part of Kant’s philosophy”
(Lange 2015/1866, 254/453).
To illuminate the legal causes of social strife, Lange’s account requires statis-
tical investigation into the various tensions that occur within society. According to
Lange, ‘class struggles’ indicate that a system has not accommodated the material
challenges of its time, thereby deploying a legal basis promoting egoistic (instead
of sympathetic) behavior. The struggle between classes would refer to “real forces”
based on unsatisfied needs and desires, requiring a change of laws so that the social
tensions are minimized: “If […] one complains of lack of promotion, and others
regard him as a vain miser, both parts are often right in a certain sense; only the
former should realize that the greater part of his reproach strikes at the social
institutions existing at the time, and the latter should bear in mind that real forces
are hidden behind such feelings, namely unsatisfied needs” (Lange 1870/1865, 49).
Lange does not value one legal system over another based on an ideal principle.
While the current system might have been a ‘good’ fit in previous times under dif-
ferent empirical conditions, it now causes ‘unsatisfied needs’ and is responsible
for promoting egoistic behavior. Instead of moral deliberations, Lange argues here
for empirical methods based on inductive reasoning to examine class struggles,
allowing us to understand an unequal distribution of goods as an indication of an
egoistic society. “My logic is probability calculation, my ethics are moral statistics,
my psychology is based on physiology; I try in one word to move solely in the exact
sciences” (Lange cited in Ellissen 1894, 106). Socialism appears as a political move-
ment based on a sensualist notion of justice, advocating to minimize class struggles
10 Elisabeth Widmer
by reforming legal norms so that material needs are satisfied more evenly, and that
societal norms promote social behavior.
But how do Lange’s aesthetic idealism and his sensualist materialism go
together? Lange is unclear on this issue, and interpreters have put forward differ-
ent interpretations. Some have argued against a systematic connection between
Lange’s sociopolitical philosophy and his aesthetic Kantianism as we find it in
Geschichte des Materialismus (Beiser 2014, 362; Klein 1994, 138; Vorländer 1974/1911,
122). If considered separately, then we find, in fact, two contradictory argumenta-
tive lines. However, Lange also claims that “materialism” is a stage in the course
of human history moving towards a purer form of (aesthetic) idealism (2015/1866,
512/910). One could accordingly interpret the relation between Lange’s aesthetic
idealism and materialistic sensualism against the background of an account that
allows for methodological pluralism. In that case, the ‘idea of harmony’ appears as
a ‘purer form’ of the sensualist principle of sympathy (Widmer 2022a, 2022b; Krauss
2022). Be that as it may, for our current purposes, the relation of the two lines of
argumentation is less important than the fact that Lange provides interpretative
allowances that place him within both respective traditions.
In his aesthetic idealism, Lange is reminiscent of the natural law tradition,
arguing for an a priori idea of harmony that structures our moral perception on the
basis of which norms conflicting with that order are presented to us as wrong. If we
interpret Lange’s social and political philosophy without considering his (what he
takes to be) ‘Kant’-inspired aesthetic idealism, political action is based on empirical
statistical knowledge, informing us about the material causes of class struggles that
need to be minimized.
4 Hermann Cohen’s Neo-Kantian Foundation for
Ethical Socialism
In the “Introduction and Critical Appendix” to Lange’s Geschichte des Materialis-
mus (1896), Cohen claims for the first time that “Kant was the true and real origina-
tor of German socialism” (1974/1896, 71). Cohen is convinced that if Kant’s notion of
practical reason were thought through, we would conclude that democratic social-
ism was the only ethically justified governmental form. In this section, I argue that
Cohen’s justification of socialism is informed by Trendelenburg’s logic and Lange’s
critical idealism.
Before examining the parallels between Cohen and Trendelenburg and Cohen
and Lange, I briefly draw attention to those aspects where Cohen differs from his
predecessors. Cohen’s ethical account differs from Trendelenburg’s Aristotelianism
‘Left-Kantianism’ and the ‘Scientific Dispute’ 11
in so far as he provides what he takes to be a ‘Platonic’ and ‘scientific’ interpre-
tation of transcendental idealism. This implies that moral principles do not orig-
inate in perceptual content. Instead, they are considered ideal rational ‘construc-
tions’ grounding the logic of the legal sciences (Falkenburg 2020, 132; Luft 2015, 29).
Cohen’s account differs also from Lange’s. Lange takes ethics as a sub-discipline of
aesthetics, thereby letting go of Kant’s categorical imperative. Cohen defends ethics
as an independent field grounded by the moral law that takes historical-cultural
norms (the ‘facts of culture’) as a starting point. Despite this difference, however,
systematic similarities suggest that in his Kantian justification of socialism, Cohen
takes inspiration from what I earlier called Trendelenburg’s principle of continuity
and Lange’s ‘critical’ methodology.
Let us first look at the systematic similarities between Cohen and Trende-
lenburg. Together with Wilhelm Dilthey, Gottlob Frege, Franz Brentano, Heinrich
Rickert, and Edmund Husserl, Cohen was one of many students of Trendelenburg
(Beiser 2013, 1). In “Zur Controverse zwischen Trendelenburg und Kuno Fischer”
(1871), the young Cohen commented on the Fischer-Trendelenburg debate. I will
not be focusing on this debate here; instead, I shall argue that when Cohen worked
out the moral law as a natural law underlying his ethical historiography, he drew
on Trendelenburg’s category of ‘movement’ or ‘coming-into-being’ and renewed
the principle of continuity on neo-Kantian grounds.
Cohen argues that ethical deliberation must not be viewed in isolation. Critical
thinking evolves in the ‘facts of science’ and the ‘facts of culture.’ Whereas Kant’s
philosophical explorations would start from a concept of experience that stands
apart from scientific facts and cultural norms, Cohen embeds his transcendental
method in the causal nexus of empirical reality. His ethical theory strives to detect
the moral foundation in historical cultural judgments as products of reason or
‘hypotheses’—as he calls them, following Plato. Cohen broadens the meaning of
5Beiser claims: “If Lange is the father of Marburg neo-Kantianism, then that tradition was based
on patricide” (2014, 357). Nonetheless, Cohen was inspired by Lange’s idea to view ethics as a critical
method that opens a new viewpoint on social relations. As his colleague Albert Görland (1869–
1952) aptly put it: “He [Lange] had already raised the central thought of critical philosophy, which
defined Cohen’s philosophy” (Görland 1912, 222).
6While Fischer claimed that the Kantian forms of space and time were merely subjective, Tren-
delenburg argued they would also count as objective principles. As recent scholarship has shown,
Cohen—who sided with Trendelenburg—had anticipated aspects of his critical philosophy in this
article (Renz 2021; Damböck 2017; Beiser 2018; Köhnke 1986).
7Cohen illustrates what he has in mind in the theoretical sphere with the following example:
“It is not the stars in the sky that are the objects which the [transcendental] method considers as
knowledge; rather, the astronomical calculations, the facts of scientific reality, are what the tran-
scendental gaze is oriented towards” (2001/1876, B27–28).
12 Elisabeth Widmer
Kantian ethics by arguing that we must scrutinize the “methodical unity” under
which “the three cultural areas [i.e., law, religion, history] were combined to test
the application of the moral law” (2001/1876, B377). Cohen’s ethical theory remains
individualistic insofar as it relies on the transcendental subject. However, his con-
ception of individual freedom is integrated “in societal and natural entanglements”
(Esser 2011, 227). Embedding critical thinking in history, however, leads to a funda-
mental problem.
How can we disentangle the moral value of ideas in history from the causal
nexus of natural and psychological components with which they are inevitably
interwoven? Here Cohen finds inspiration in Trendelenburg’s concept of ‘move-
ment’ or ‘coming-into-being’ (1981/1904, 44). In various passages, Cohen argues that
the moral ideal—his novel interpretation of the ethical concept of universality—is
the rational concept that vouches for continuation in history. Cohen attempts “to
present Kant’s epistemological justification of ethics in the psychological movement
[Bewegung] in its developments” (1981/1904, vi, emphasis added). He states: “The
movement in law and state contains an immanent appeal to an external forum[…].
We shall later claim the concept of history for this purpose” (1981/1904, 439). In
another passage, Cohen claims: “It is history on which the idea of perpetual peace
is grounded, and it vouches for the continuous movement” (1981/1904, 454). Similar
to Trendelenburg’s dynamic conception of reason, Cohen supports a “dynamic”
concept of reason, allowing for an ethical point of view of the ideas in the history
of humanity (Luft 2015, 168).
More specifically, Cohen formulates a novel interpretation of the moral law
in the second edition of Kants Begründung der Ethik. He criticizes Kant’s ethical
theory for using materialistic terms that have led to a flawed depiction of the moral
law. His formulation of the moral law goes as follows: “No person is allowed to
be used ‘merely as a means.’ Every person must always, at the same time in the
administration of the moral world, be treated as ends in themselves” (2001/1876,
B279–280). Cohen takes two Kantian formulations of the moral law as comprising
the individual’s fundamental right to be treated as an end in themselves in society:
the formula of humanity and the formula of the kingdom of ends. Whereas Kant’s
moral law asks what I ought to do, the Cohenian law asks how a moral world must
be ‘administrated’ to protect human dignity, thereby adding a social and teleologi-
cal aspect to the moral law (pace Furner 2019). Cohen provides an evaluative prin-
ciple that allows us to identify developments stemming from a free moral will, even
if the norm in question is materialized in history and thus entangled in the causal
nexus. Those norms that are conceptually incoherent with the moral law must be
dismissed if society is to progress.
By setting out the development of culture in its progressiveness, Cohen gives
up on the systematic distinction between law and morality. Since for Cohen there
‘Left-Kantianism’ and the ‘Scientific Dispute’ 13
is only one fundamental moral right that allows for a critical examination of nor-
mative concepts, he argues that Kant’s conception of “coercion did not grow on
the ground of transcendental freedom” (2001/1876, B395). Some passages later, he
claims: “Kant did not exercise that free, unbiased, sovereign criticism of positive
law that gives his transcendental criticism its true life and its powerful fruitfulness”
(2001/1876, B399). Like Trendelenburg, Cohen accuses Kant of mistakenly “separat-
ing law and morality,” which hindered him from seeing the potential of the moral
law as a “natural law” underlying all cultural practices (2001/1876, B399). Concepts
consistent with the moral law are manifestations of ethical ideas, grounding the
continuation of human progress.
In Ethik des reinen Willens, Cohen adds a political component to the ideal
notion of the moral law or the ‘pure will.’ The substantive prescriptive concepts
constituting society change continuously; however, the state’s task has been and
will always be the same, namely, to protect the dignity of its citizens. To signify the
political implications, Cohen introduces the concept of ‘Allness’ (Allheit). Cohen’s
conception of the moral law relies on an adaptation of Trendelenburg’s category of
coming-into-being. “The state [Allheit] is the universal institution in which history
represents the human race and brings it to its development” (1981/1904, 378). Tren-
delenburg argues that legal systems have a shared focus on an ethical end, thereby
taking norms in their autonomous origin and their materialized form. Similarly,
Cohen uses the methodological concept of the ideal state to disregard the causal
factors on which moral ideas in history rely. The idea of the moral state functions
as a “lighthouse” and an “anchor for the flood of history. It contains the last magic
key for the continuation of humanity” (1981/1904, 503). The materialized rational
norms differ fundamentally over time. However, the focus on an absolute end that
grounds our will to systematize norms enables one to regard the history of human-
ity in its moral-progressive continuation. In other words, ‘Allness’ is the concept
8We remember that Trendelenburg takes the category of coming-into-being as the cognitive
capacity to grasp an object in its state between ‘being’ and ‘not-being,’ or a norm in its state
between ‘autonomy’ and ‘heteronomy.’ In the same vein, Cohen’s ‘principle of continuity’ grasps
laws in their state between rationality and historicity. Christian Damböck characterizes the ‘prin-
ciple of continuity’ accurately as a “compass” that allows us to “crystallize” the continuous aspects
“independent of the empirical context” (2017, 144). Hartwig Wiedebach characterizes continuity in
Cohen similarly as the “concept of universality” under which “constitutive statements about the
reality of nature” become possible (2000, 434). According to Geert Edel, the principle of continuity
is a judgment about reality directed towards the “absolute” (2010, 269–270). The principle of con-
tinuity allows us to grasp the rational foundation in historical forms, thereby opening the view on
the manifestation of rationality in history. The difference between the theoretical and the practical
realms is that the the former deals with a unity that grounds determining laws, while the latter is
based on a concept of unity that grounds rules based on free causation.
14 Elisabeth Widmer
that provides continuity in the cultural domain. Like Trendelenburg, Cohen bases
his practical philosophy on an ethical principle, claiming that we recognize the
lasting moral value of norms under the ideal concept of the state, the ‘Allness.’
Let us now turn to the critical component in Cohen’s ethics reminiscent of
Lange’s idealism. Cohen agrees with Lange that ethics must proceed critically. In
contrast to the historicist camp that engages with an inductive method to examine
empirical facts, Cohen’s methodology starts from historically evolved and empiri-
cally manifested legal facts—the ‘facts of culture’—and discusses their underlying
ethical end. Cohen’s Kant-inspired critique of empirical concepts is well illustrated
by his critique of capitalism.
Cohen criticizes the conceptual presuppositions of a capitalist legal system in
which persons and objects are confused. Inheritance laws in capitalist societies are
based on the misleading assumption that a “person’s will could be materialized”
in an object (1981/1904, 608–609). “Capital,” on the other hand, “no longer seems to
be a mere thing; it becomes a person because it acts like persons” (1981/1904, 609).
Concerning the concept of labor, Cohen argues that the employer would gain, for a
certain amount of time, “ownership” over the worker (ibid., 605). Thus, under capi-
talist law, objects are treated as persons, and laborers are reduced to their physical
skills and thus treated as objects—which is incompatible with the moral law. This
conceptual problem causes—to use Cohen’s words—“serious damage” (1981/1904,
607).
Cohen does not use the moral law to test maxims; instead, he critically ana-
lyzes prescriptive concepts constituting the legal framework of a capitalist society,
thereby reminding us of the function of the ‘idea of harmony’ in Lange’s account.
On the back of his teleological and social interpretation of the moral law (or later
the ‘Allheit’), Cohen’s investigation of prescriptive notions involves, similar to
Lange, a critical moment, as it allows us to identify inhumane prescriptive con-
cepts (like capital and the idea of inheritance) that hinder society from progressing.
Cohen’s interpretation of the moral law functions as a conceptual criterion against
which misleading prescriptive concepts are criticized. This also grounds Cohen’s
9The characterization of Cohen’s ethics as a form of ideal rational construction involving deduc-
tive critique is based on a teleological understanding of rationality. This aligns with recent works
on Cohen’s theoretical philosophy. Scott Edgar has recently set out various ways in which Cohen
engages with history, thereby claiming that all variants are grounded on a “teleological concep-
tion of history” approximating the—entirely ideal—“thing in itself” (Edgar 2022, 160). In a similar
vein, Ursula Renz has argued that, according to Cohen, the historian needs “to be a philosopher”
who “demands a philosophical judgment that transcends historical exposition” (Renz 2021, 699).
In Christian Damböck’s characterization of Cohen as part of a philosophical movement he calls
“German Empiricism,” we find the discussion of the ideal foundation of historical judgments exem-
plified in Cohen’s understanding of unity. The Platonian ideal of unity provides us with the neces-
‘Left-Kantianism’ and the ‘Scientific Dispute’ 15
reform-based understanding of socialism: We gradually gain insights into immoral
prescriptive concepts manifested in legal laws through ethical deliberation. Society
progresses by bringing them in a consistent order with the moral law.
Cohen’s concept and usage of the ideal state (Allheit) comprise systematic com-
ponents of Trendelenburg’s logic and Lange’s idealism. Trendelenburg’s work is
reflected in Cohen’s focus on norms considered in their autonomous origin despite
their heteronomous appearance. The critical component of Lange’s idealism is
reflected in Cohen’s conceptual critique, illuminating wrong turns or misleading
developments.
5 Historicist Tendencies in Rudolf Stammler’s
Kantian Socialism
A different picture emerges in Stammler’s Wirtschaft und Recht nach der materi-
alistischen Geschichtsauffassung (1896) and Die Lehre vom richtigen Rechte (1902).
Stammler was deeply impressed by the transcendental method as Cohen had devel-
oped it in Kants Theorie der Erfahrung (1871), and, in many ways, their views align.
Stammler agrees with a critical interpretation of Kantian philosophy that grounds
the logic of cognition on an a priori idea of systematicity. In the same vein, he
follows Cohen’s rejection of psychological approaches. In Rechts- und Staatstheo-
rien der Neuzeit (1925), Stammler explicitly criticizes the concept of Volksgeist as it
“mistakes the mind for a psychic phenomenon” (1925, 50–51). Like Cohen, Stammler
rejects purely psychological approaches for their unscientific foundation and
argues that the legal sciences should deal with the transcendental logic of legal
judgments. However, as I will show in this section, Stammler’s position differs from
Cohen’s account in two crucial respects: he rejects Cohen’s proposal of an ethical
foundation of law and argues for the need to include inductive research on the
historical and empirical conditions of a society.
sary requirement under which the historical-empirical reality is presented to us in a unified way
(Damböck 2017, 158). Damböck argues that “the fact of culture […] is the precondition; Cohen is not
concerned with the external reconstruction but the internal [ideal] condition, its ‘origin’” (2017,
140). Cohen thinks that all theorizing is based on an ideal notion of systematic unity. For this reason,
he has been characterized as a “rational constructivist” (Luft 2015, 29). While the natural sciences
strive toward the ideal of a systematic unity of scientific principles (grounded on the thing-in-it-
self), we rationally create norms under the teleological ideal of a systematic unity of ends (as it is
set out in his novel interpretation of the moral law). Ideal rational constructions do not exclude
Cohen’s focus on the historically formed ‘facts of culture.’ Cohen believes that ethical deliberation
must start from empirical facts about the social world (i.e., from given positive laws).
16 Elisabeth Widmer
Stammler differentiates between the ‘formal’ or ‘legal’ and the ‘material’ or
‘economic’ side of sociality. On a formal level, Stammler excludes ethics from the
legal sphere. In a letter from 1892 to Stammler, Natorp suggests reading Cohen’s clas-
sification of the cultural sciences in Kants Begründung der Ethik (KBE) (Stammler
1896 [1892], 213). In his response, Stammler writes: “Having reread [Cohen’s] jus-
tification of ethics [in KBE], I see now clearly that moral laws cannot exist in our
experience at all” (1896 [1892], 213). The moral law—taken as the formal principle
governing the internal state of the moral agent—could never “come into congru-
ence” with the social norms that are “empirically conditioned” (1896 [1892], 213).
According to Stammler, Kant rightfully differentiated between the a priori condi-
tions of legal judgments, dealing with heteronomous and external laws regulat-
ing the social sphere, and the a priori conditions of moral judgments, which deal
with internal laws. His understanding of legality, however, also differs fundamen-
tally from the Kantian natural law that draws on an account of external freedom.
Stammler’s Wirtschaft und Recht (1896) grounds an epistemic ‘natural law,’ which
goes as follows:
By natural law, I understand legal propositions which contain the theoretically correct law
under empirically conditioned circumstances; which do not yet have positive force merely
because of this insight but function as a source of law demanding a change or reorganization
of the law in force. (Stammler 1896, 185, emphasis added)
Stammler’s ‘theoretically correct law’ is not based on a practical account of freedom
that sets the foundation for normative statements. Instead, the ‘theoretically correct
law’ is a scientific ideal that grounds the telos of both the natural and legal sciences.
Stammler argues that there is only one type of cognition (Erkenntnisart), theo-
retical reason, that grounds the foundation of law. Stammler’s ‘theoretically correct
law’ presupposes free agents capable of setting rules for themselves. However,
instead of providing an account of legality that deduces a system of rights from a
positive account of freedom (as we find in Cohen and Kant), Stammler takes legal
norms in their substantive and changing nature as they appear in the sphere of
causality. This does not mean that Stammler gives up on a neo-Kantian foundation
of law. However, he objects to Cohen’s claim that there are two types of cognition—
theoretical and normative cognition—and argues that, as in the natural sciences,
we should pursue a systematic formulation of laws that grounds a just regulation
of the empirical (economic) conditions:
The regular repetitions of certain phenomena, united to the respective unity, are called laws.
And all individual laws are only possible by the fact that a generally valid lawfulness of
nature lies at the basis without which every single law of nature in itself would be completely
groundless and without the provable value of knowledge. (Stammler 1896, 350)
‘Left-Kantianism’ and the ‘Scientific Dispute’ 17
Stammler formulates the ‘theoretically correct law’ as a principle that follows from
the same account of systematicity as the natural realm.
While Cohen opts for deductive judgments and focuses on ideas and their
(un)ethical instantiation in society, Stammler’s deductions are based on empirical
facts that need to be obtained with empirical methods. The underlying idea is the
following. While the economy follows its own rules, it is our task to observe eco-
nomic relations and bring the “blind forces” under control (1896, 29). According
to Stammler, economic conditions constitute social conditions. However, it is pos-
sible to intervene in such naturally evolved economic processes by regulating the
market. Stammler illustrates this with the following analogy: “If a mountain stream
runs the risk of flooding the lowlands, we calculate and construct streambeds to
contain and control the flow” (1896, 50). Social nature, too, demands regulations;
the legal system has the power to regulate and fix misguided developments by
steering them in the right direction (1896, 51–52).
What follows from the ‘theoretically correct law’ under ‘empirical conditions’
is an account of social progress that requires two methodologies: (i) an examination
of empirical facts requiring inductive reasoning; and (ii) rendering the acquired
facts deductively under the idea of a more unified or balanced picture of society.
“[N]ot the exact collection of isolated data is what makes a good historian, but rather
the right synthesis of the universal concept of law” (1896, 23). Once we realize that
“under this economic foundation […] there still hovers the old legal order of times
long past” (1896, 47), we have the epistemic means to overcome the social tensions
expressed in class struggles. In this vein, Stammler emphasizes that, technically
speaking, it would be wrong to call the capitalist system “unjust”; instead, it would
be more apt to call it “economically outdated” (1896, 47–48). Progress is the “human
attempt” to “regulate and guide the otherwise wild and unbridled forces of social
production” (1896, 30).
The reason why Stammler thought of the ‘theoretically correct law’ as a prin-
ciple free from a normative conception of justice remains unclear. More impor-
tantly, Stammler’s engagement with the empirical material that combines induc-
tive examinations of class struggles and a deductive rendering of empirical facts
under the idea of systematicity reflects his educational background in the Histor-
10Stammler was indecisive in terms of how his epistemological foundation related to ethics or
normative questions more generally. This provoked a harsh critique from Max Weber, who accused
Stammler of falling back on “an ‘unconditional’ point of view” that Stammler sought to prevent
(Weber 1985, 302). In Lehre des richtigen Rechtes (1902), Stammler refrains entirely from a natural
law principle, thereby defining four a priori principles that refer merely to the application of the
law (1902, 208, 211). Stammler does not mention Weber explicitly. However, this decision might have
been a reaction to Weber’s critique.
18 Elisabeth Widmer
icist School of Savigny. Cultural progress does not involve the contemplation of a
practical law, guiding the morally right path. Instead, the progress of legal systems
is measured by a theoretical principle and informed by empirical circumstances.
Stammler reads Lange against this background when characterizing him as a the-
orist of ‘social materialism.’ Following the empiricist line of argument in Lange, he
claims: “The lawfulness of the social life of people is, according to the doctrine of
social materialism, a regularity of economic phenomena” (1896, 29). For a success-
ful rendering of empirical facts that inform our political action, we need to conduct
inductive examinations of the “economic phenomena” constituting a society, which
allows us to gain insights into the origins of class struggles (1896, 29).
Stammler’s epistemological principle of the ‘theoretically correct law’ grounds
a principle of cultural progress according to which bringing empirical forces into
systematic order leads to a more balanced satisfaction of needs. Reminiscent of
Savigny and Lange, then, Stammler’s account focuses on the origins of class strug-
gles in order to gain information on how to reform the legal system.
6 The ‘Scientific Dispute’ and ‘Left-Kantianism’
The ‘scientific dispute,’ to use Natorp’s term, started in the early 1890s. Stammler
was from the outset frustrated by Cohen’s attempt to ground all social norms on an
ethical foundation without acknowledging their a priori systematic differences.
In this section, I highlight the main divergences between Cohen and Stammler. I
argue that their disagreement is characteristic of a more general intellectual atmos-
phere of the pre-war era when philosophers were seeking a justification for social-
ism on Kantian grounds.
First, their views on the demarcation between law and morality fundamentally
differ because of their different outlooks on what the critical method is supposed
to achieve. Cohen is inspired by Trendelenburg’s category of coming-into-being
and Lange’s critical use of the idea of harmony, which allows identifying concep-
tual inconsistencies with the moral law or ‘Allheit.’ Cohen does not simply forget to
include the coercive and heteronomous characteristics of positive laws and he does
11Stammler’s “social materialism” is introduced by a quote by Lange that says: “Materialism is the
first, the lowest, but also the comparatively firmest stage of philosophy” (1896, 25; Lange 2015, 553).
12Natorp tries to function as a mediator between these two positions. In Sozialpädagogik in 1899
and in the article from 1913, Natorp claims that the disagreement was solvable on a modal level.
While Cohen’s ethics were concerned with claims of logical necessity, Stammler moved in the
empirical world dealing with probability claims (Natorp 1913, 68).
‘Left-Kantianism’ and the ‘Scientific Dispute’ 19
not deny the power given to institutionalized rules. He rejects a systematic separa-
tion of law and morality because accepting a foundation that allows for coercive
and heteronomous laws would undermine the critical aspect of his methodology
that identifies conceptual inconsistencies. Thus, for methodological reasons, Cohen
denies the Kantian distinction between the internal, ethical, autonomous, and sub-
jective domain of morality on one side and the external, legal, and coercive realm
on the other.
Stammler adopts a different view of what the critical method is meant to
achieve. It is not the task of philosophy to identify ethical inconsistencies; its task is
instead to engage with empirical facts provided by the empirical sciences in order
to understand the origins of class struggles that lead to an uneven satisfaction of
needs. The a priori conditions of legality do not include a natural law based on a
practical account of justice. His conception of the ‘theoretically correct law’ is meant
as an epistemological principle that grounds social progress. Thus, Stammler, too,
has a methodological reason to reject the Cohenian idea of a universal moral prin-
ciple underlying his critique of the capitalist legal system because it would under-
mine the fact that legal contents are continuously changing.
Second, their varying conceptions of legality trace back to different method-
ological approach for dealing with ‘facts.’ Cohen historicizes reason to show that
some social norms are based on ethical judgments, even though they are interwo-
ven with causal factors. This provides the critical foundation upon which societal
developments are evaluated. Cohen’s critique engages with ideas materialized
in the legal foundation constituting society. However, his methodology is based
on deductive reasoning. Stammler’s methodology, on the other hand, is based on
deductive reasoning, and yet asks additionally for inductive investigations of the
social reality (i.e, statistical knowledge). While Cohen sees contradictions as based
on ethical deliberation, Stammler takes the inconsistencies between law and
economy as empirically measurable phenomena, materialized in the social class
struggles. Stammler’s account is shaped by the requirement to obtain empirical
knowledge with the methods of the empirical sciences; Cohen’s historical facts of
culture are taken as a given.
Third, based on their different methodologies, Cohen and Stammler criticize
capitalism on different levels. Cohen’s ethical critique is based on a concept of change
that requires action from the bottom up. His methodology is meant to critique sin-
gular developments instead of a whole economic system—an idea illustrated in
his affirmative attitude towards workers’ unions (Genossenschaften). Stammler’s
13Similarly, Schwarzschild argued that for Cohen, “history […] must be a rational science” (1956,
426).
20 Elisabeth Widmer
socialism, however, includes a top-down approach as it is meant to investigate
economic systems and the ‘suitedness’ of the corresponding legal system. In more
modern terms, one could say that Cohen’s socialism has more liberal tendencies,
arguing for the individual right always to be treated as an end in oneself. Mean-
while, Stammler’s socialism seeks to change the economic flow on a systematic
level, thereby moving to an economic system that is centrally organized and one
that gives more power to the state. Although on a practical level, these approaches
are not mutually exclusive, their underlying method with which they come to these
conclusions is different: Cohen’s socialism is based on the deliberation about laws
that protect the individual’s fundamental right to a dignified life. Stammler’s con-
ception of socialism is meant to correct the laws that create empirically measurable
societal problems and injustices.
Their differences show that Marburg neo-Kantian socialism was not a coherent
current, seeking an ethical justification for socialism. Admittedly, there is reason to
regard them as part of the same philosophical school considering their critical-ide-
alist take on Kant and their reaction to a form of idealism that did not engage suf-
ficiently with the empirical aspects of society. However, like Trendelenburg and
Savigny, they differed in age and disciplinary background, and thus their philoso-
phies diverged fundamentally regarding the conception of law, history, and their
view of what the critical method was meant to achieve. Their theories belonged,
consequently, to two distinct camps: an ethical and epistemic justification of social-
ism. Thus, it is misleading to speak of a coherent school of thought.
Another reason to break with current characterizations is that Cohen and
Stammler were not the only ones to offer left-wing interpretations of Kantian
socialism at the time. Up until the First World War, a wide variety of original left-
wing interpretations of the Kantian system emerged in the German-speaking world.
Austro-Marxists like Otto Bauer (1881–1938) and Max Adler (1873–1937) sought to
combine Marxism with Kantian thought. Although their approaches might have
been influenced by the Marburg School, their positions were distinct in crucial
respects. Adler, for example, criticized Cohen for refraining from the materialist
elements of Kant’s philosophy of history. In his view, the materialist elements in
Kant’s works provided the most valuable foundation for combining Kant with Marx.
In “Idee zu einer allgemeinen Geschichte in weltbürgerlicher Absicht” (1784/1959),
Kant argues that historical progress is based on human social nature characterized
by the tendencies to socialize and isolate. Here sociality is understood in a natural
rather than an ethical sense, claiming that we have learned over time that we can
reach our goals more efficiently by working together. This “social-psychological”
conception of human progress provides, according to Adler, valuable insights that
would “complement Marx’s conception of dialectical materialism” (Adler 1904/1976,
167).
‘Left-Kantianism’ and the ‘Scientific Dispute’ 21
Other Kant-inspired socialist theories were developed by Conrad Schmidt
(1863–1932) and Ludwig Woltmann (1871–1907). Schmidt rebuked Cohen for his Kan-
tian-ethical justification of socialism. For Schmidt, Cohen’s philosophy was built on
a “rigid dogmatism of the moral system derived from pure reason,” which would
virtually “rape” the concept of ethical consciousness taken in a causal and hetero-
geneous manner (Schmidt 1974/1900, 105). Despite his rejection of Kant’s practical
reason, Schmidt argued that Marxism needed to be reformulated based on Kant’s
theoretical philosophy. Woltmann, by contrast, agreed with Cohen’s ethical justi-
fication of socialism. However, he criticized Cohen’s critical-idealist approach to
Kant, arguing instead for a metaphysical reading of Kant’s moral philosophy, which
he considered the “orthodox” reading (Woltmann 1974/1900, 117–118).
Even Natorp, Karl Vorländer (1860–1928), and Franz Staudinger (1849–1921),
who drew on a Cohenian account of socialism in their own work, identified funda-
mental problems in Cohen’s position. Vorländer criticized Cohen for not sufficiently
differentiating between his own claims and Kant’s (Vorländer 1974/1911, 286).
Staudinger was critical of Cohen’s theoretical philosophy (Staudinger 1986/1902,
292) but aligned with Cohen’s ethics. However, he developed it further into a cul-
tural theory of social layers he called “social cells” (Staudinger 1914, 145).
The Marburg School was not a coherent movement, either philosophically or
politically. The question of how far other left-Kantian approaches align with the
natural law and the historicist camps is a question for further research. The crucial
point is that Cohen and Stammler were part of a broader philosophical current that
was striving to provide a Kantian alternative to Marxist socialism that is neither
defined by an ethical theory nor tied to Marburg.
7 Summary and Outlook
In this paper, I have argued against current views suggesting either that Marburg
neo-Kantian socialism was a coherent ‘school,’ or that all Kantian approaches
developed in the decade prior to the First World War were based on an ethical
foundation. I have focused on the ‘scientific dispute’—as Natorp described it in
1913—between two theories within the Marburg School: Hermann Cohen’s ethical
and Rudolf Stammler’s historicist justification of socialism, and explained their the-
ories by tracing their origins.
14I have focused only on left-Kantian positions just prior to the First World War. For left-Kantians
who came before the Marburg School, see Fichte (1845/1800). In contemporary debates, see, e.g.,
van der Linden (1988), Wayne (2014), Ypi (2014), Love (2017).
22 Elisabeth Widmer
By shedding light on these different Kantian theories of law, history, and poli-
tics, I have argued that it is better to give up the term ‘Marburg neo-Kantian social-
ism,’ which gives the misleading impression of a cohesive school of thought. To
signify the variety of left-wing political interpretations of Kant right before the
outbreak of the First World War, I have suggested that we subsume these positions
under the umbrella term ‘left-Kantianism.’
Left-Kantianism at the turn of the twentieth century remains an underexplored
topic. With this paper, I have endeavored to establish the importance of reconsid-
ering classifications that conceal the variety of positions within a movement that
was dissatisfied with the philosophical implications of Marxism and so sought a
Kantian justification of socialism. My choice of terminology—‘left-Kantianism’—is
deliberately open since further research is required on individual thinkers before
a clear and adequate definition of this philosophical current can be provided. This
paper has attempted to make a first step towards that end. I hope that others will
follow my lead.
Acknowledgments: I am grateful to Martin Kusch, Niels de Haan, Simon Mussel,
and two anonymous referees for their helpful comments. Moreover, I thank the
audience present at my talk at the Philipps University of Marburg in November
2021, the participants of the workshop “Economic Pluralism” at McMaster Univer-
sity in Canada in September 2022, and those present at the conference “Von der Her-
meneutik zur Wissenschaftstheorie” in September 2022 at the University of Vienna.
Funding: Funder Name: KanDem: The Kantian Foundations of Democracy, Funder
Id: , Grant Number: The Research Council of Norway/ 324272
Adler, M. 1904/1974. ‘Kant und der Sozialismus.’ In H.Sandkühler and R. de la Vega (eds.), Marxismus
und Ethik. Frankfurt am Main: Suhrkamp, 157–192.
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