Adeeb Kasem meditates on the implications of Marx’s ‘Theses on Feuerbach’ and argues that historical and dialectical materialism form part of a broader pragmatic materialist framework for Marxist praxis.
Introduction
Marx’s Theses on Feuerbach outlines the research program for Marx’s theory of practice,1 which we may describe as his pragmatic materialism. Dialectical and historical materialism are essential moments of a distinct and broader pragmatic materialism, which is nonetheless also dependent upon dialectical and historical materialism.
Marx’s materialism falls in the broad category of pragmatism because Marx theorizes knowledge of the world as inseparable from practice in the world.2 Events can be known by means of practices. Knowledge is gained by practice. Knowledge is not gained by interpretation. It is by the attempt to change the world, and the success or failure of this attempt, that knowledge is gained. This knowledge, in turn, is a resource for further attempts to change the world.
As a research program, pragmatic materialism is the systematic accumulation of such knowledge, especially in the context of the socio-political project of changing the world, also known as revolution.
Pragmatic materialism is a materialist historicism. As such, its fundamental unit of analysis is the event; that which happens. The event is fourfold, having four degrees of freedom: social practices, social conditions, social relations, and social forms.
Although Marx’s pragmatic materialism encompasses more phenomena than merely social practices, the adjective “pragmatic” and the noun “pragmatism” are nevertheless fitting, not only because social practices are interdependent with social conditions, social relations, and social forms, but also because of the decisive role of social practices in history, that is, in making history.
Pragmatic materialism can be divided into two broad categories: evental ontology and evental epistemology. Evental ontology means the ontology of events, the study of the modes of existence of events. Evental epistemology means the epistemology of events, the study of the methods of knowing events.
Evental ontology may be further subdivided into four precise categories: social practices, social conditions, social relations, and social forms, which are the modes of existence of events. Dialectical and historical materialism are included in this scheme as moments of the category of social forms. The scientific method applied to the study of history more or less amounts to evental epistemology. The scientific method applied to the study of human history is the method of knowing historical events.
Bearing in mind that some of the theses encompass more than one category, we may reorganize the theses roughly according to the categories they meditate upon.
Theses 1, 3, 4, 5, 6, 7, 8, 9 and 10 meditate upon evental ontology. Theses 1, 5, 8 and 9 meditate upon social practices. Theses 3 and 6 meditate upon social conditions. Theses 6, 9 and 10 meditate upon social relations. Theses 4, 6 and 7 meditate upon social forms. Theses 2 and 11 meditate upon evental epistemology.
Social Practices
In Thesis 5, which restates Thesis 1 in more concise form, Marx writes, “Feuerbach, not satisfied with abstract thinking, appeals to sensuous contemplation; but he does not conceive sensuousness as practical, human-sensuous activity.” Sensuousness or the sensuous, that which can be observed through the senses or perception, is nothing other than the empirical. Marx argues that if “sensuous contemplation,” that is, empirical thinking or cognition, can be conceived, then we can also conceive of human activity as empirical activity.
If one can conceive of objects and cognition as empirical, then one should readily be able to conceive of practices as empirical. Yet for most of the history of Western philosophy, this has not been the case. We could consider the empiricism of Hume, Locke, or Berkeley, in which the basic empirical unit is the object, whether one calls it sensation, idea, or whatever else.3 For Spinoza, the basic empirical unit is the object, which he calls the body.4 On the other hand, the idealism of Descartes begins with the bare fact of mental activity, which is simply called thinking, as Descartes arrives at his first thesis that he is a thinking thing.5
We could even point to philosophical theories after Marx. Brentano’s and Husserl’s phenomenology are implicitly or explicitly an idealism built around the concept of intentionality or directedness, the basic unit of mental activity.6 Nietzsche’s meta-psychology of the will to power, which is, alternatively, the basic structure of mental activity and, as psychical force, the basic unit of mental activity.7 We can even consider Freud’s psychoanalysis, which ultimately reduces all human activity to mental activity, more specifically to the libido, whether conceived as the discharge of psychical energy or as the topographical-structural-psychical base or id of the human being.8
In this context, Marx’s theorization of human activity as primarily empirical (that is to say, material), as opposed to primarily mental, is a profound rupture with the history of Western philosophy, even when considering contemporary Western philosophy, major strains of which are built on top of the idealisms of Husserl, Nietzsche, and Freud.
In Thesis 9, Marx writes, “The highest point attained by contemplative materialism, that is, materialism which does not comprehend sensuousness as practical activity, is the contemplation of single individuals in ‘civil society.’” Marx, following Hegel, takes philosophy beyond the stagnant waters of the individual mind with an empirical and social conception of human activity that puts the individual human being in contact with other human beings, or at least allows us to conceive of this contact.9
And yet, this pragmatic materialism, which is easy enough to state, is difficult to adhere to as a basis for analysis, since a thousand theoretical considerations mislead us into one or another obscure form of scholastic mysticism wherein certain theoretical questions and indeterminate abstractions predominate over observations of determinate, concrete practices.
As Marx writes in Thesis 8, “Social life is essentially practical. All mysteries which mislead theory into mysticism find their rational solution in human practice and in the comprehension of this practice.” In a certain sense, pragmatic materialism is the impoverishment of theory, since it strips away from theory, or robs theory of, all purely theoretical concerns. In a certain sense theory is richer than practice, but these riches all amount to false riches, counterfeits, because they are not consciously conceived of with reference to practice. On the other hand, practice, as the unimpeachable limit of theory, permanently prevents theory from taking off into the infinite.
As a corollary of the impoverishment of theory, merely theoretical or textual critique, or “deconstruction” if you will, pales in comparison to critique in practice, critique carried out in practice, or what Marx describes in Thesis 1 as “practical-critical activity,” which he also describes as “revolutionary” activity. We may also describe revolutionary activity as practical-deconstructive activity, that is, deconstruction in practice or deconstruction carried out in practice.
The impoverishment of theory is also the impoverishment of text, the insufficiency of text. The insufficiency of text also means that a deconstruction limited to the text is likewise insufficient. Practice is always outside the text, impoverishing the text.10 Therefore, it is only in the domain of practice as practical-deconstructive activity, as revolutionary activity, that deconstruction can be significant.
In the context of our everyday lives, practical-deconstructive activity is the taking-apart of capitalist society, whether brick by brick, or with a wrecking ball, or with dynamite. Practical-deconstructive activity ultimately aims towards dismantling the relatively firm and permanent foundation of capitalist society, its economic base, and not merely the cultural and political superstructure that rests upon this foundation.11
Social Conditions
In Thesis 3, Marx theorizes social conditions as distinct from, but nonetheless dependent on, social practices. Marx is in agreement with the materialist formulation that human beings are the products of social conditions and that, therefore, changed human beings are the products of changed social conditions. However, he finds this formulation incomplete insofar as the concept of practice is entirely missing from it. Marx’s pragmatic materialism adds that it is human beings who, through social practices, change their social conditions.
In Thesis 3, Marx writes, “The coincidence of the changing of circumstances and of human activity can be conceived and rationally understood only as revolutionizing practice.” Circumstances, along with upbringing, constitute what we call social conditions, that is, the social conditions or social context in which human beings exist. When social conditions change, they do not change spontaneously by themselves, but rather, by means of human activity. The practical-deconstructive activity of revolution is nothing other than the event of human beings changing their social conditions through social practices.
In Thesis 6, Marx meditates upon social relations and social forms as well as social conditions. Marx’s comment on social conditions in Thesis 6 is oblique. Critiquing Feuerbach, Marx writes that Feuerbach defines the human being and religious sentiment in an ahistorical, and therefore illegitimate, manner. Marx writes that Feuerbach illegitimately “abstract[s] from the historical process” and thereby presupposes ahistorical abstractions.
In the context of Thesis 3, the “historical process,” or to put it more simply, history, theorized in Thesis 6, is nothing other than social conditions and the change of social conditions. History as process, historical process, is the process of change. More specifically, history is the process whereby social conditions change, which also presupposes the intermediary of social practices.
Social Relations
However, Thesis 6, considered by itself, or in the context of Theses 9 and 10, yields a different concept of history, history as the change of social relations, the historical process as the process whereby social relations change. An abstract or isolated human individual, such as Feuerbach conceives of, is only possible if one abstracts from history, that is, presents an ahistorical interpretation. The human being in history exists in the midst of social relations.
The concept of history as the change of social relations is the corollary of the concept of history as the change of social conditions because social relations are the corollary of social conditions. Social relations and social conditions are inseparably linked. Moreover, the historical process, the process whereby social relations change, is the same as the process whereby social conditions change: the intervention of deconstructive social practices.
In Thesis 6, Marx writes that the essence of the human being is “the ensemble of social relations.” The essence of the human being is external to the single, individual human being. The relations between individual human beings, external to individual human beings, is the constitutive essence of individual human beings. Human beings are produced by social relations.
Moreover, social relations exist together determinately in an ensemble, totality, or collection. Social relations, as a totality, collection, or ensemble, is a matrix, a womb, or generative force. The matrix of social relations is a generative force that produces individual human beings. The totality of social relations, as the essence of the human being, that which produces human beings as such, is the womb or the generative force that produces human beings.
Let’s return to what Marx writes in Thesis 9 and put it in dialogue with what he writes in Thesis 10: “The standpoint of the old materialism is ‘civil’ society; the standpoint of the new is human society, or associated humanity.” Marx’s critique of contemplative materialism or the old materialism is also his critique of Feuerbach, who is the targeted representative of contemplative materialism.
In the light of Thesis 6, meditation upon “single individuals in ‘civil society’” can only mean meditation upon isolated human individuals, human individuals abstracted from history or conceived of ahistorically. “Civil society,” then, is merely a collection or aggregate of isolated human individuals, and as such it is just as ahistorical a concept as the isolated human individual. “Civil society,” thus conceived, is a “society” without social relations, a concept of “society” with all reference to social relations subtracted from it.
In lieu of isolated human beings and “civil society,” Marx’s new materialism, his pragmatic materialism, meditates upon socially associated or related human beings and “human society.” “Human society” is society with social relations, a concept of society with reference to the social relations constituting it. A “human society” is a society constituted by a matrix of social relation. Therefore, a “human society” is a society in history, a historical society.
Social Forms
Although meditation upon social forms is implicit in Theses 4 and 6, it is explicit in Thesis 7. In Thesis 7, Marx writes “that the abstract individual which [Feuerbach] analyzes belongs in reality to a particular form of society.” Feuerbach analyzes a human being and mistakenly identifies them as an abstract, isolated, ahistorical individual. In reality, that human being concretely exists in history and in relation to other human beings. As such, they belong to a particular form of society, or social form, in history. In historical materialism, social forms are defined in terms of the relations of production dominating their basis, with the five main social forms being the primitive communal society, the slave society, the feudal society, the capitalist society, and the socialist society.12
In Thesis 4, Marx outlines the rudiments of what would later come to be known as dialectical materialism and historical materialism. Marx writes that “the inner strife and intrinsic contradictoriness” at the basis of a particular form of society generate particular ideologies. For example, the theory of a given religion, with its religious and imaginary world, lifts off from the real and secular base of a particular form of society in order to establish “itself in the clouds as an independent realm,” that is, establish itself as “real” in the imagination, thereby substituting itself for the actual, secular real world, via an act of the imagination.
However, as we shall see, Marx’s concept of base and superstructure in Thesis 4 is somewhat at odds with Marx’s “Preface” to A Contribution to the Critique of Political Economy.13 We defend the latter view against the former, since the latter is more representative of both Marx’s major works, such as Capital and The German Ideology, as well as later developments of Marxist social science.
In Thesis 4, Marx writes, “Thus, for instance, once the earthly family is discovered to be the secret of the holy family, the former must then itself be criticized in theory and transformed in practice.” Here Marx misidentifies the base of the ideology of the holy family in Christianity with the actual family as it existed in Christian societies, which also suggests an arbitrariness in selecting the material bases for other cultural superstructures. But as Marx makes clear in his “Preface,” the real material basis for any given cultural superstructure is the corresponding economic system which enables it to operate.
In the “Preface” Marx writes, “The sum total of these relations of production constitutes the economic structure of society, the real foundation, on which rises a legal and political superstructure and to which correspond definite forms of social consciousness. The mode of production of material life conditions the social, political and intellectual life process in general.”14
In the light of Thesis 4, part of Thesis 6 obliquely meditates upon social forms insofar as it obliquely discusses culture. In Thesis 4, Marx criticizes Feuerbach’s concept of human being as a purely natural being conceived of in terms of the human species. The implication of Marx’s critique is that human beings are not wholly determined by nature. In today’s terminology, we would say that human beings are determined primarily by culture, as opposed to nature. Human beings are cultural beings.
By the term “culture” we include the ethical and the aesthetic as well as the legal and the political and their corresponding forms of social consciousness, and the ethical, aesthetic, social, political, and intellectual life process in general. The question of culture is a question of social forms. Cultures or cultural factors belong to particular social forms. In light of the “Preface,” cultures or cultural factors are identifiable as superstructures built upon an economic base, whether they reproduce the base or oppose the reproduction of the base. Moreover, human beings, as cultural beings, are to a great extent influenced by or shaped by cultural factors.
Therefore, the secret of the holy family is not the earthly family, but the economic systems that allowed and continue to allow the mythology of the holy family to operate socially, albeit in different ways: first the slave mode of production, then the feudal mode of production, and then the capitalist mode of production, which of course continues to this day. The earthly family exists alongside the holy family as a part of a determinate superstructure, a point first elaborated at length by Engels in his book The Origin of the Family, Private Property and the State.15
Religion, as a theory, is a superstructure built on top of a secular, economic base insofar as it lifts off from this secular, economic base. Marx historicizes religion insofar as he theorizes religion as a social institution originating in history in a particular form of society. Marx thereby also paves the way for the abolition of religion, since by implication religion as a social institution can be destroyed in history in another form of society. What has its beginning in history also has its ending in history.
The superstructure, however, is not homogeneous. The superstructure is heterogeneous, meaning it harbors contradictions within itself, just as the base harbors contradictions within itself. In Thesis 4, Marx writes that the secular basis of religion must “first be understood in its contradiction and then, by the removal of the contradiction, revolutionized in practice.” For both the earthly family and the holy family to be negated, the contradictions of the real secular basis of both must be analyzed, then removed, thereby being revolutionized in practice. That real secular basis is the economic system, which today means capitalism, which is specifically what must first be criticized in theory and then transformed in practice.
Religion, as superstructure, exists in contradiction with other concepts in the superstructure. The class struggle in the economic base is also expressed in the superstructure as a struggle between ideas. The existence of contradiction in the superstructure means that ideas are objects of class struggle.
The superstructure is simply what is built on top of the base. The superstructure does not necessarily reproduce the base, its conditions of existence. The primary contradiction in the superstructure is between the theory that reproduces the base and the theory that opposes the base and the reproduction of the base. Although the transformation of the base is ultimately a matter of practice, the revolutionary intervention of practice is not possible without revolutionary concepts, the theoretical critique of the base.
Evental Epistemology
In Thesis 2, Marx restates the scientific method in the context of his materialist pragmatism. Marx’s pragmatism is a materialism insofar as Marx affirms the existence of truth. As such, Marx’s materialist pragmatism is opposed to idealist pragmatisms which deny the existence of truth, as does, for example, the philosophy of Richard Rorty.16 Marx’s materialism, his affirmation of truth, is also a pragmatism insofar as it is practice that distinguishes truth from untruth.
In Thesis 2, Marx writes, “The question whether objective truth can be attributed to human thinking is not a question of theory but is a practical question. [Human beings] must prove the truth, i.e., the reality and power, the this-worldliness of [their] thinking in practice. The dispute over the reality or non-reality of thinking which isolates itself from practice is a purely scholastic question.” Marx’s evental epistemology is the impoverishment of theory in epistemology, just as his evental ontology is the impoverishment of theory in ontology.
To raise the question of practice is also to deftly dismiss much of the history of Western philosophy, which, insofar as it concerns debates over truth without reference to practice, remains purely scholastic. Marx’s curt but apt dismissal can be read today as a curt but apt dismissal of dominant trends of both analytic and continental philosophy. Schools of analytic philosophy, such as Karl Popper’s work, that reject the formulation of truths based on empirical evidence on the grounds that such evidence-based thinking is merely so much naivety and “verificationism” are just as divorced from the reality of practice as schools of continental philosophy that reject the concept of truth on the grounds that there are only interpretations but no correct interpretation.17
While Marx clearly indicated that Hegel could be salvaged from the wreckage of continental philosophy, Marx came too early in history to be able to comment upon analytic philosophy. Tentatively, using the Theses as our guide, we claim that from the wreckage of analytic philosophy we can salvage the long-neglected logical positivists or logical empiricists Moritz Schlick and Friedrich Waismann, who were radical advocates of precisely the kind of verificationism that is rejected by the dominant currents of contemporary analytic philosophy.18
Thesis 11 is typically quoted as a stand-alone quote. However, the proper context of Thesis 11 is in the context of Marx’s own work and more specifically of the other Theses on Feuerbach, not to mention the works, both theoretical and practical, of Marx’s successors, such as Lenin, Stalin, and Che Guevara.
In the context of the other Theses, but particularly in relation to Thesis 2, Thesis 11 is a meditation upon evental epistemology. In Thesis 11, Marx writes, “The philosophers have only interpreted the world in various ways; the point, however, is to change it.” Both merely interpreting the world in various ways and decisively changing the world are practical questions. The truth, reality and power, the this-worldliness of the project of changing the world, as opposed to merely interpreting it, is proven in practice.
The philosophers have only interpreted the world in various ways insofar as they disputed over the reality or non-reality of thinking isolated from or abstracted from practice, that is, as a purely scholastic exercise.
The correct interpretation of the world, which impoverishes interpretation as such, that is, theory as such, is proved in practice. It is only with such pragmatic clear-sightedness that deconstructive practice can intervene in the world in order to change the world, or what is second-best, make an attempt to change the world.
In historical context, events can be known as indices of the change of social conditions, that is, indices of social change. In social context, events can be known as indices of class struggle. As an index of social change, an event can be classified as either contributing to social change or as obstructing social change. Moreover, it can be classified as such objectively, since social change and class struggle are objective events known by practices.
Research Questions
In conclusion, from Marx’s Theses on Feuerbach, we may extract the following research questions. Together they constitute the “Pragmatic Materialism Research Program,” which summarizes and reiterates as questions the main points of our meditations on Marx’s Theses.
- What practices are there? How can the empirical facts be described in terms of the social practices or practical activities of the human being(s) involved? How can the empirical facts be described in terms of empirical activities or empirical practices?
- How can the theorization of the event(s) being studied remain focused on the social practices constitutive of the event(s) being studied? How can we describe the event(s) in terms of practices? What is the history of the event being studied? How is the event being studied related to past events? How are the ideas involved in the event being studied themselves events?
- What are the practices constitutive of the society being studied? Are the practices being studied practical-critical activity (revolutionary) or practical-uncritical activity (non-revolutionary)?
- What are the social conditions that produced the human being(s) being studied? How are those human being(s) maintaining or changing the social conditions that produced them?
- How do(es) the individual human being(s) being studied exist in relation to other human beings? What is the matrix of social relations constitutive of the society being studied? What are the social relations that produced the human being(s) being studied? How does the matrix of social relations constitute or produce the individual human being(s) being studied?
- What particular form of society do(es) the human being(s) being studied belong to? What are the contradictions of the society being studied? How does the society being studied reproduce itself? What concepts oppose the reproduction of the society being studied? What are the cultural factors that influenced or shaped the human being(s) being studied?
- Where can we place the events being studied as indices of class struggle? Where can we place the events being studied as indices of social change? Does your hypothesis correspond with reality, that is, with real events? Does your hypothesis have explanatory power? Does it account for a sufficiently comprehensive amount of real events? Does it accurately predict real future events?
- Karl Marx and Friedrich Engels, Marx and Engels Collected Works, Volume 5: Marx and Engels 1845-47 (London: Lawrence and Wishart, 2010), 6-8. Throughout this essay, all quotations from the Theses on Feuerbach are from the version printed in the text cited here, which is the version edited by Engels.
- Catherine Legg and Christopher Hookway, “Pragmatism,” The Stanford Encyclopedia of Philosophy (Summer 2021), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/sum2021/entries/pragmatism/.
- William Edward Morris and Charlotte R. Brown, “David Hume,” The Stanford Encyclopedia of Philosophy (Winter 2023), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/win2023/entries/hume/; William Uzgalis, “John Locke,” The Stanford Encyclopedia of Philosophy (Fall 2022), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/fall2022/entries/locke/; Lisa Downing, “George Berkeley,” The Stanford Encyclopedia of Philosophy (Fall 2021), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/fall2021/entries/berkeley/.
- Steven Nadler, “Baruch Spinoza,” The Stanford Encyclopedia of Philosophy (Spring 2024), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/entries/spinoza/.
- Gary Hatfield, “René Descartes,” The Stanford Encyclopedia of Philosophy (Spring 2024), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/entries/descartes/.
- Wolfgang Huemer, “Franz Brentano,” The Stanford Encyclopedia of Philosophy (Spring 2019), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/spr2019/entries/brentano/; Christian Beyer, “Edmund Husserl,” The Stanford Encyclopedia of Philosophy (Winter 2022), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/win2022/entries/husserl/; Pierre Jacob, “Intentionality,” The Stanford Encyclopedia of Philosophy (Spring 2023), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/spr2023/entries/intentionality/.
- Friedrich Nietzsche, The Will to Power, trans. Walter Kaufmann (New York: Random House, 1967), §1067. “This world is the will to power — and nothing besides! And you yourselves are also this will to power — and nothing besides!”
- Alain de Mijolla, “Libido,” in International Dictionary of Psychoanalysis, edited by Alain de Mijolla (New York: Thomson Gale, 2005), 967-970.
- Paul Redding, “Georg Wilhelm Friedrich Hegel,” The Stanford Encyclopedia of Philosophy (Winter 2020), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/win2020/entries/hegel/.
- Gary Aylesworth, “Postmodernism,” The Stanford Encyclopedia of Philosophy (Spring 2015), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/spr2015/entries/postmodernism/.
- Leonard Lawlor, “Jacques Derrida,” The Stanford Encyclopedia of Philosophy (Summer 2023), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/sum2023/entries/derrida/.
- Josef Stalin, “Dialectical and Historical Materialism” (1938), Marxists Internet Archive, https://www.marxists.org/reference/archive/stalin/works/1938/09.htm. “Five main types of relations of production are known to history: primitive communal, slave, feudal, capitalist and socialist.”
- Karl Marx and Friedrich Engels, Marx and Engels Collected Works, Volume 29: Marx and Engels 1857-61 (London: Lawrence and Wishart, 2010), 261-266.
- As quoted in Josef Stalin, “Dialectical and Historical Materialism” (1938), Marxists Internet Archive, https://www.marxists.org/reference/archive/stalin/works/1938/09.htm.
- Karl Marx and Friedrich Engels, Marx and Engels Collected Works, Volume 26: Marx and Engels 1882-89 (London: Lawrence and Wishart, 2010), 129-276.
- Bjørn Ramberg and Susan Dieleman, “Richard Rorty,” The Stanford Encyclopedia of Philosophy (Fall 2023), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/fall2023/entries/rorty/.
- Stephen Thornton, “Karl Popper,” The Stanford Encyclopedia of Philosophy (Winter 2023), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/win2023/entries/popper/; Peter Gratton, “Jean François Lyotard,” The Stanford Encyclopedia of Philosophy (Winter 2018 Edition), Edward N. Zalta (ed.), https://plato.stanford.edu/archives/win2018/entries/lyotard/.
- Thomas Oberdan, “Moritz Schlick,” The Stanford Encyclopedia of Philosophy (Fall 2022 Edition), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/fall2022/entries/schlick/; Richard Creath, “Logical Empiricism,” The Stanford Encyclopedia of Philosophy (Winter 2023 Edition), Edward N. Zalta & Uri Nodelman (eds.), https://plato.stanford.edu/archives/win2023/entries/logical-empiricism/.