1 Introduction

The aim of this paper is twofold,Footnote 1 namely, to discuss Rudolf Carnap’s ideas regarding so-called geistige Gegenstände—i.e., the products of the human mindFootnote 2—in his Der logische Aufbau der Welt (Carnap 2005, originally published in 1928, hereafter Aufbau) and to contextualise these ideas in relation to the German sociologist Hans Freyer.Footnote 3 I argue that even a cursory comparison of Freyer’s Theorie des Objektiven Geistes (first edition 1923, second 1928) and Carnap’s Aufbau reveals striking similarities. Given Carnap and Freyer’s shared experiences in the German Youth Movement (Jugendbewegung) and their continuous friendship and discussions from the early 1910s until 1933, these similarities seem neither superficial nor coincidental.

I do not wish to claim that Freyer had the most significant impact on the Aufbau in any sense or that we must read the entire book from Freyer’s perspective. We certainly cannot do that. There are only a few paragraphs on geistige Gegenstände in the Aufbau, and the book seeks to incorporate many of the major philosophical and scientific tendencies of the early twentieth century.Footnote 4 However, one must recall that Carnap was in continuous intellectual exchange with Freyer while they were both at work on their respective book projects. Thus, if we were to consider Carnap’s approach to the geistige Gegenstände in particular and to the human sciences (Geisteswissenschaften) in general, Freyer would be of utmost importance given the role he played in Carnap’s formative years.

My paper is organised as follows. Setting the scene for later discussion, in Sect. 10.2, I outline the relationship between Freyer and Carnap in the context of their engagement with various groups of the German Jugendbewegung and Carnap’s overall attitude towards the human and social sciences. Section 10.3 offers a detailed reconstruction of Carnap’s approach to the geistige Gegenstände and Geisteswissenschaften. Section 10.4 discusses Freyer’s research that specifically addresses the human and cultural sciences while emphasising the various similarities and overlaps between his and Carnap’s work.

It should be noted that the personal and intellectual connections between Carnap and Freyer extend beyond questions of the geistige Gegenstände in the Aufbau. In fact, Christian Damböck has recently argued for a new reading of the Aufbau that interprets the book in the context of the Dilthey School:

Although Carnap himself was interested mainly in the problems of logic and the philosophy of the natural sciences, the community in which he worked until he went to Vienna in 1926 was neither a community of neo-Kantian philosophers nor of logicians or philosophers of the natural sciences but a community of the Dilthey school that were interested in history of philosophy (Herman Nohl […]), pedagogy (this is also the case for Herman Nohl and Carnap’s lifelong friend Wilhelm Flitner), aesthetics (Franz Roh, also a lifelong friend of Carnap, was one of the intellectual promoters of “neue Sachlichkeit”) and sociology (Hans Freyer) (Damböck, 2012, 67-68).Footnote 5

The so-called Dilthey School and the persons influenced by it opposed neo-Kantianism in the German philosophical scene. According to Damböck, these Diltheyian scholars are “somewhat intermediate between classical empiricism and the accounts of the (neo-)Kantian tradition. [Hence] the intellectual background of the Aufbau is even broader than it is suggested by those classical interpretations” (Damböck, 2012, 70). In the 1920s, Hans Freyer was closely linked to the Dilthey School. Prior to that period, his intellectual mentors were historian Karl Lamprecht and Friedrich Nietzsche, the latter interest based on his friendship with the philosopher Raoul Richter, who wrote an important two-volume Nietzsche monograph. Thus, when reconstructing the personal and intellectual connections between Freyer and Carnap, one should include the less-studied relationship of Carnap (and his Aufbau) to this line of the “continental” or German intellectual tradition.

This reading of Carnap’s Aufbau that emphasises its relation to the human sciences has a long history, one that reaches back to the Vienna Circle meetings. Thus, the following sections of my paper could be viewed as an attempt to reconstruct the context necessary to interpret the following seemingly peculiar entry from Carnap’s diaries. On 19 December 1929, Carnap noted, “With Feigl to Neurath. Neurath grumbled over my presentation of the ‘Geisteswissenschaften’ in the ‘Aufbau.’ This is too idealistic for him; he had some points to attack: he gets to name Dilthey: ‘moral,’ ‘state,’ ‘manifestation’” (RC 025-73-03).

2 Setting the Scene: Carnap and Freyer’s Friendship

On 11 October 1922, Carnap wrote to Heinrich Scholz that he “holds [Freyer] in very high esteem, both as a person and a scholar” (RC 102-72-10). Although there is no evidence of Carnap and Freyer’s friendship in their published works, and Carnap did not preserve their correspondence, Carnap’s recently transcribed diaries indicate that the acquaintance of the two men dates to their time in the German Youth Movement. Carnap’s involvement in the German Youth Movement and its effect on his philosophical and personal development are well documented.Footnote 6

The Youth Movement is a general term that covers various groups, circles, and more or less formal associations. The very first group to form was the so-called Wandervogel, an association of self-organised high-school students in Fin de siècle Berlin. Its members viewed themselves as anti-bourgeois, adhered to the back-to-nature movement and characterised their stance as a “revolt by withdrawal” (Landauer, 1978, 25). The movement banded together those

German schoolboys and students who rejected their parents’ new-found prosperity and their narrow conformism. It had no explicitly political agenda, more a cultural-political one; bands of students headed off into the countryside to experience nature and ‘authentic’ peasant culture. They sang traditional German wandering songs. […] The ‘bourgeois’ drugs—coffee, tobacco, alcohol—were proscribed. (Carnap never touched them for the rest of his life.) (Carus, 2007b, 20f.)Footnote 7

When the Wandervögel reached the age of entering university, several of them founded the Free Academic Association (Akademische Freischar) in 1907, which sought to combine the romantic ideals of the Wandervogel with an intellectual perspective. In later years, former Wandervögel joined the Free German Youth (Freideutsche Jugend) at the open-air festival on the Hoher Meißner in October 1913. In addition to the Wandervogel and its branches, two more of the attending groups must be mentioned. One is the Free School Community Wickersdorf (Freie Schulgemeinde Wickersdorf), a progressive school (somewhat similar to the later Waldorf Schools) founded and headed by Gustav Wyneken in 1906. The other is the so-called Free Student Movement (Freie Studentenschaft), which also served as a scholarly oriented community for students not wanting to join one of the traditional student corporations; the Free Students fought for the democratisation of the university by demanding equal representation. In addition, they created their own intellectually informed culture and values in the spirit of the Wandervogel.Footnote 8 One of their leaders was Hans Reichenbach, who later became the internationally recognised central figure of the Berlin Group of Logical Empiricism.

In 1909, Carnap moved from Wuppertal-Barmen to Jena with his mother and younger sister. In Jena, he found himself in an intellectually and emotionally stimulating atmosphere. The rose garden of the family home on Jena’s Lindenhöhe quickly became a meeting place for the students who gathered around the well-known publisher Eugen Diederichs. One year earlier, Diederichs had initiated the so-called Sera Circle (Serakreis), which consisted of young Freistudenten and former Wandervögel at the University of Jena.Footnote 9 The group sang folk songs together and undertook long hikes in the woods and mountains around Jena in an effort to internalise the pathways and natural environment of the land.Footnote 10 The exact date Carnap joined the Serakreis is unknown, but in June 1910, he was—as can be gathered from a photograph—part of a group of Sera friends led by Diederichs who participated in the twenty-fifth anniversary celebration of the founding of the Goethe Society in Weimar.Footnote 11

In 1911 and 1912, Carnap spent three semesters at the University of Freiburg. While attending classes with the neo-Kantian scholars Jonas Cohn, Georg Mehlis, and Heinrich Rickert, he also became a cofounder of the Akademische Freischar Freiburg.Footnote 12 Returning to Jena in fall 1912, Carnap transformed the Serakreis into the Jena branch of the Akademische Freischar and became their revered leader. (The various local Freischar groups eventually joined the umbrella organisation, the Deutsche Akademische Freischar.) It is difficult to imagine how Carnap could have led a group of young people bound by a shared Weltanschauung and simple companionship (Geselligkeit). However, according to unpublished parts of his autobiography, it was much easier for him than one would have expected. He wrote:

I did not feel myself strong and productive enough to transform singlehandedly the group of friends [i.e., the Vienna Circle, A.T.T.] into a living community, sharing the style of life which I wanted. Although I was able to play a leading role in the philosophical work of the group, I was unable to fulfill the task of a missionary or a prophet. Thus, I often felt as perhaps a man might feel who has lived in a religious[ly] inspired community and then suddenly finds himself isolated in the Diaspora and not strong enough to convert the heathen (Carnap 1957, [UCLA], Box 2, CM3, folder M-A5, B35-B36).Footnote 13

While Carnap had not succeeded in playing a transformative role similar to that of a “prophet” in a “religiously inspired community” in Vienna, he was quite able to do so in Jena. As one of his best friends, Wilhelm Flitner (1986, 142), recalled, Carnap took over as leader of the Serakreis in 1913. In retrospect, Carnap viewed his engagement with various groups of the Youth Movement enthusiastically:

For those whose work is of a purely theoretical nature, there is the danger of a too narrow concentration on the intellectual side of life, so that the properly human side may be neglected. I think it was very fortunate for my personal development during these decisive years that I could participate both in Freiburg and in Jena in the common life of such fine and inspired groups of the Youth Movement (Carnap, 1957, [UCLA], Box 2, CM3, MA-5, B32).

Looking back at his formative years as a student in Jena and Freiburg, Carnap made it very clear that the Jugendbewegung equipped its members with a specific attitude rather than theoretical doctrines. This experience was one that thousands of young Germans had in different groups, and it exerted a lifelong effect on everyone “who had the good luck to participate” (B34-B35). What Carnap learned is that one should not blindly accept any doctrine, knowledge, and heritage, that everyone has the right and ability to revise and/or ask regarding the reasons for everything, to reshape and rebuild (Aufbau) their cultural and social environments and to question conventions or norms.Footnote 14

It was through his friend Walter Fränzel in 1908 that Freyer learned about Eugen Diederichs and the Serakreis in Jena.Footnote 15 Freyer’s biographer Jerry Z. Muller observes that Diederichs was Freyer’s “extra-academic mentor, the publisher of two of his early books, and […] responsible for Freyer’s first contribution to a major periodical” (Muller, 1987, 32). Freyer joined the Leipzig Freistudentenschaft during the 1909–1910 academic year. Due to his friendship with Fränzel, he participated in a rather lively exchange with various members of Jena’s Serakreis. In 1911, after finishing his dissertation, Freyer accepted a temporary position as a substitute teacher at the Freie Schulgemeinde Wickersdorf, whose principal at that time was the reform pedagogue Martin Luserke.

In October 1913, Freyer attended the First Free German Youth Day (Erster Freideutscher Jugendtag) on the Hoher Meißner mountain in Central Germany, where various groups affiliated with the Jugendbewegung held a “counterfestival” to the nationalistic celebration of the centenary of the Battle of Nations in Leipzig. In addition to the Serakreis, many young men and women representatives of the Akademische Vereinigung Jena and Marburg, the Deutsche Akademische Freischar, the Freie Schulgemeinde Wickersdorf, and the Austrian and German Wandervogel attended this first open-air festival of the German Youth Movement. Among these individuals was Rudolf Carnap.Footnote 16 As Carnap later recalled, one aim of the youth meeting was “to find a way of life which was genuine, sincere, and honest, in contrast to the fakes and frauds of traditional bourgeois life; a life guided by the own conscience and the own standards of responsibility and not by the obsolete norms of tradition” (Carnap 1957, [UCLA], Box 2, CM5, B31-B32).

Members of the German Youth Movement often kept up their friendships via circulated and published letters, pamphlets and reports. In addition, there were many different periodicals and journals (often short-lived) to read and contribute to.Footnote 17 Freyer was no exception, and a number of his early essays appeared in forums related to the German Youth Movement.Footnote 18 Carnap also intended to publish an article in Political Circulars (Politische Rundbriefe), founded in 1918 by Karl Bittel, a member of the left-wing Jugendbewegung. However, his essay, entitled “Deutschlands Niederlage – Sinnloses Schicksal oder Schuld?” (“Germany’s Defeat – Meaningless Fate or Guilt?”), never appeared.Footnote 19

The first mention of Freyer in Carnap’s diaries is from October 1913, when both of the young men were first in Vollradisroda (near Jena) and then in Weimar, where they rehearsed and performed Goethe’s Satyros at a Festspiel.Footnote 20 Later, Carnap and Freyer met on and off either at the gatherings of the Serakreis or for philosophical discussions at various universities. During the First World War, they met in Berlin, then in Leipzig (1920, 1925), Jena (1921), and Kiel (1923).Footnote 21 After the war, Freyer discussed various questions and issues—relating to pedagogy, politics, art, culture and the rational shaping of the world—with Carnap, Walter Fränzel, Herman Nohl, and Franz Roh, who all belonged to the intellectual circle of Wilhelm Flitner. These scholars, who shared a social and cultural context, provided one another with information regarding philosophy and history according to their individual interests and educational backgrounds. As Carnap noted in the unpublished parts of his autobiography, during this period of his life, most of his friends and discussion partners came from the humanities and social sciences.Footnote 22 In addition to the historian Karl Lamprecht, there was another important intellectual figure for Freyer, the previously mentioned Herman Nohl, who provided him with exhaustive information regarding Dilthey and the latter’s views on Weltanschauung.Footnote 23

Freyer, Carnap, Roh, and Flitner also formed a Kommunikationsgemeinschaft (discussion group) in the summer of 1920 at Wiesneck near Buchenbach, where all of them were living while seeking to complete their on-going projects on worldviews, the history of arts, pedagogy, and economy, respectively.Footnote 24 In August, Carnap organised a workshop where he discussed Wilhelm Ostwald’s “system of the sciences” with Flitner, Roh, and Freyer. The attendees exchanged their views on the relations between logic, mathematics, the natural sciences and the human/cultural sciences. While Carnap emphasised a general scheme and order of the sciences, Freyer discussed ethics as a science and the cultural sciences. Based on a detailed study and reconstruction of the Buchenbach meeting and its context, Hans-Joachim Dahms argues that the meeting was “a decisive turning point in Carnap’s life” (Dahms, 2016, 171).

In September 1927, Carnap sent two manuscripts to Flitner, Freyer, and Roh, asking for their opinions.Footnote 25 According to Carnap’s remarks in the cover letter, these manuscripts were the final versions of the Aufbau and Scheinprobleme in der Philosophie. Thus, Freyer was familiar with Carnap’s research prior to the publication of the second edition of his Theorie. Since we know, however, that Carnap started to work on his Aufbau in 1922 (see Carus, 2007, 139–140; Carnap, 1963a, 16), it is plausible that Freyer already knew about Carnap’s project during the early 1920s. Carnap’s diaries (and his reading list, RC 025-03-05) indicate that he frequently consulted Freyer’s Theorie with great interest in 1923, and he made many notes in the margins of his copy (which unfortunately seems to be lost). At the end of October 1923, he also visited Freyer and spent time with him, just as he did in 1925 (May and October), about the time he was completing his habilitation in Vienna; notably, his habilitation treatise (Habilitationsschrift) was an early version of the Aufbau.Footnote 26

There are at least two additional reasons to claim that Freyer and Carnap exchanged ideas regarding the Aufbau project and the relation between the natural and human sciences in general. In a letter from Roh to Flitner, dated July 1920, Roh writes as follows:

It’s a pity that the expected program which C[arnap] was (or had) to reconcile with FREYER did not work out after all. From the 3 big complexes in which we were involved, to which shall we turn now? To politics? To ethics? To the system of sciences? Freyer mentioned in a letter that we shall appreciate ethics and the value of science (quoted from Priem & Glaser, 2002, 171).

More details regarding their planned project are not to be found. However, the previously mentioned three big complexes—politics, ethics, and the value of sciences—seem to cover the academic and personal interests of Carnap and Freyer (this conclusion seems to be strengthened by the Buchenbach meeting, which took place just a month later in August). Nonetheless, Freyer’s Theorie, which will be discussed below, and Carnap’s Aufbau must still be treated as their authors’ independent research projects and research results during and after their various meetings and conversations.

Furthermore, André W. Carus quotes a 1922 letter from Carnap to Heinrich Scholz that also contains interesting remarks on the project of the planned system of the Aufbau and in which Carnap wrote as follows:

[t]he present discipline of philosophy combines very heterogeneous subjects, after all. I see two main parts, in particular: 1) ethics, aesthetics, philosophy of religion, metaphysics; one might say: philosophy of culture and nature, or the science of life- and world-conceptions. 2) according to the traditional terminology: logic and epistemology. […] Although I have a lively interest in [1], and have made myself familiar with its questions and attempted solutions through books, lectures, seminars, and a number of conversations with friends – but [this was] always just from personal interest, from a desire for personal self-improvement, not as a productive researcher or a reproductive teacher (quoted after Carus 2007, 158f.).

This letter supports the idea that Carnap (1963a, 10) had a lively interest in the philosophy of culture, life, and the human sciences and that he followed the current debates on these questions and disciplines. Accordingly, he had a good deal to discuss with a social scientist, and Freyer turned out to be just the partner who could explain the cultural world’s constitution in line with Carnap’s thoughts. However, before discussing Freyer’s view, I wish to reconstruct Carnap’s ideas regarding so-called geistige Gegenstände.

It should be noted that whereas Carnap remained friends with Roh and Flitner throughout his life, his friendship with Freyer ended in the early 1930s.Footnote 27 During a visit to Ernst Mannheim, who was Freyer’s student and a cousin of the famous Hungarian sociologist of knowledge Karl Mannheim, Carnap learned of Freyer’s involvement in the National Socialist Movement.Footnote 28 Because of this political involvement, Carnap severed all personal ties with Freyer and subsequently only received information about him through mutual friends, such as Roh and Flitner.Footnote 29

3 Carnap on geistige Gegenstände in the Aufbau

Carnap took a lively interest in the philosophical problems of culture and society although this interest remained mostly a personal and not a professional concern.Footnote 30 I argue that Carnap’s approach to the theoretical questions of the human and social sciences should be at least partially understood in connection with his intellectual exchange with Freyer. I support the ideas of Thomas Uebel and others that Carnap’s approach in the Aufbau was more than simple (or typical) “logico-empirical reductionism.”Footnote 31

Carnap’s aim in the Aufbau was “to establish a ‘constitutional system’ [Konstitutionssystem], that is, an epistemic-logical system of objects or concepts” (§1). A constitutional system is “a step-by-step ordering of objects in such a way that the objects of each level are constituted from those of the lower levels” (§2); it is a multi-layered theory of knowledge, a theory of “the structure and functioning of human cognition set up as a layered architecture of simple and complex factual capacities and faculties of knowledge” (Zuh, 2015, 45). Carnap’s layered conception includes at least four different layers (see §25; in fact, he would introduce more layers and object types). When we frame our system from an epistemological viewpoint (as done in Carnap’s book), on the first level, there are autopsychological objects (§§106–122). On the second layer, we find physical objects. The third level consists of so-called heteropsychological objects that are the same as autopsychological objects but belong to an individual other than oneself. The fourth layer is that of the geistige Gegenstände.

These layers are built upon one another, and although each layer has its own laws, properties, and structure, all the layers are connected: geistige Gegenstände can be reduced to heteropsychological objects, which in turn can be reduced to physical objects, which can be reduced to autopsychological objects.Footnote 32 This reduction is not ontological but logical; it concerns sentences regarding these various objects and their logical relationships. Constitution theory embraces the idea that (empirical) statements describe different spheres of objects (§29) that “are brought into a stratified order within the constitutional system by constituting some of these objects on the basis of others” (§41).

Carnap maintained in the Aufbau that “for philosophy, the most important types of objects, outside of the physical and the psychological ones are the ››geistige Gegenstände‹‹ in the sense of ››cultural‹‹, ››historical‹‹, ››sociological‹‹ objects” (§23, translation modified). Among geistige Gegenstände, Carnap counts “individual incidents and large-scale occurrences, sociological groups, institutions, movements in all areas of culture, and properties and relations of such processes and entities” (§23), various customs and habits (§§24, 150), the object of the state (Staat, §151), technology, economics, law, politics, language, science, and religion (§151).

In the constitutional system’s layered structure, “geistige Gegenstände are not composed of psychological (much less physical) objects. They are of a completely different object type; geistige Gegenstände belong to object spheres other than the physical and the psychological objects” (§23). This distinction is important since it affects how we can obtain knowledge of geistige Gegenstände given that “there are different constitutional levels and forms” (§23). Both psychological objects and geistige Gegenstände are subject-bound; i.e., they require “bearers.” However, “in contrast to the psychological objects, bearers [of geistige Gegenstände, A.T.T.] may change: a state or custom can persist even though the bearing subjects perish and others take their place” (§23).

To account for our knowledge of geistige Gegenstände, Carnap introduced two relations between geistige and other objects: “manifestation” and “documentation” (§24). He also considers the case when the recognition of a geistiger Gegenstand is mediated through another geistiger Gegenstand but claims that this mediation is recognised through manifestations and documentations (§55). His example is the religion of a given society, which, in addition to physical documentations, is recognisable through the following manifestations: “the representations, emotions, thoughts, volitions of a religious sort which occur with the members of th[e] society” (§55). Using manifestation and documentation, Carnap indicates that one’s knowledge of geistige Gegenstände is closely related to one’s knowledge of heteropsychological objects, which, in turn, can be reduced to physical objects. He describes the manifestation relation as follows:

A geistiger Gegenstand which exists during a certain time, does not have to be actual (i.e., manifested) at all points during this span. The psychological processes in which it appears or ››manifests‹‹ itself, we shall call its (psychological) manifestation. The relation of the (psychological) manifestation of a geistiger Gegenstand to the object itself, we shall call the manifestation relation (Aufbau, §24).

One way to obtain knowledge about geistige Gegenstände is to identify their psychological manifestation. Carnap’s example is the custom of hat-lifting:

This relation holds, for example, between the present resolve of a man to lift his hat before another man, and the custom of hat-lifting. This custom does not exist merely during those moments in which somebody somewhere manifests it, but also during the times in between, as long as there are any persons who have the psychological disposition to react to certain impressions by greeting somebody through lifting their hats. During the times in between, the custom is ‘latent’ (Aufbau, §24).

The custom of hat-lifting, which represents a geistiger Gegenstand, is manifested in psychological objects, for example, in dispositions. One’s knowledge of this (hetero)psychological object is based on physical occurrences. In this case, such physical occurrences are the subject’s report of his disposition to lift his hat, the generation of the right (and physically observable) conditions for hat-lifting, and observation of the motion defined as hat-lifting. In the first case, another important relation is involved, namely, the reporting relation: “By this we mean the relation between a bodily motion and a psychological process, provided that this motion indicates through speech, writing, or other sign-giving the presence and the nature of the psychological process” (§57). Note, however, that even if physical events and objects are involved in the manifestation, “closer scrutiny shows that […] the psychological manifestation relation is fundamental” (§24).

The other relation, the documentation relation, exists between physical objects and geistige Gegenstände when the physical objects are the documentations of the geistige Gegenstände. Carnap terms “documentations of a geistiger Gegenstand those permanent physical objects in which the mental life [das geistige Leben, A.T.T.] is, as it were, solidified: products, artifacts, and documents of the mental [des Geistigen, A.T.T.]” (§24). He provides several examples of what counts as a documentation: “The documentations or representations of an art style consist of the buildings, paintings, statues, etc. which belong to this style. The documentation of the present railroad system consists of all stationary and rolling material and the written documents of the railroad business” (§24). The documentation relation is of special importance because most of the objects that the human sciences are concerned with no longer exist. For example, the ideas of Renaissance no longer exist in the way they did in the fifteenth century. However, certain products of this cultural, political, and artistic movement do still exist as physical objects—such as buildings, written records, artistic creations, illustrations—and through their existence, they document the corresponding ideas.

Heteropsychological and physical objects are indicators that mediate between geistige Gegenstände and other types of object (§56). Therefore, in any epistemological situation, or more precisely, any rational reconstruction of epistemological processes, psychological (and physical) objects possess epistemic primacy (§54) over geistige objects. While the natural sciences claim that geistige Gegenstände are composed of psychological processes (similar to a physical entity consisting of its molecules), Carnap argues that there is more to geistige Gegenstände than their heteropsychological manifestations and physical documentations:

The awareness of the aesthetic content of a work of art, for example a marble statue, is indeed not identical with the recognition of the sensible characteristics of the piece of marble, its shape, size, color, and material. But this awareness is not something outside of the perception, since for it no content other than the content of perception is given; more precisely: this awareness is uniquely determined through what is perceived by the senses. Thus, there exists a unique functional relation between the physical properties of the piece of marble and the aesthetic content of the work of art, which is represented in this piece of marble (Aufbau, §55).

Here, Carnap takes the side of the human sciences: the “human sciences tend to consider [geistige, A.T.T.] entities as entities of a special type, not just as a sum of psychological processes” (§56). The essence of the Carnapian epistemological-logical constitutional system is that the various objects of knowledge can be constituted from the autopsychological domain, while all layers remain an autonomous and special object sphere. Carnap “considers the position of human sciences justified” (§56).

Therefore, when Carnap envisaged the geistige Gegenstände and reduced them to heteropsychological and physical objects, he did not disassemble them into their elements but rather translated the sentences that codified them. When translating sentences about geistige Gegenstände into sentences about heteropsychological and physical objects, one does not reproduce the sense or meaning (Sinn) of the statements; what must remain the same are the logical value (i.e., the extension, the truth-value of the sentence) and occasionally the epistemic value of the original sentence (§§50, 51, 56). Carnap also notes that “the philosophy of the nineteenth century did not pay sufficient attention to the fact that the geistige Gegenstände form an autonomous type. […] Only the more recent philosophy of history [Geschichtsphilosophie, A.T.T.] (since Dilthey) has called attention to [it]” (§23, translation modified). Although he discusses geistige Gegenstände and the human sciences in many paragraphs of the Aufbau, his considerations and ideas remain rather sketchy:

We cannot here give an explicit account of these constructions. The reason for this is that the psychology (or phenomenology) of the cognition of cultural items [die Psychologie (oder Phänomenologie) der Kulturerkenntnis] has not been researched and systematically described to the same degree as the psychology of perception. Thus, we give only a few examples and indicate briefly how they could be generalized. These indications may suffice, since we are here mainly concerned with the possibility of constitution [emphasis mine, A.T.T.] of geistige Gegenstände from psychological objects and since we are less concerned with the question precisely what forms these constitutions must take (Aufbau, §150).

Carnap did not work out the details of the constitution of geistige Gegenstände. He just set the stage for the human sciences and noted the prerequisite conditions for such a project. In light of Carnapʼs interest in questions of the human and social sciences, one could ask why he did not in fact work out the details of the constitution of geistige Gegenstände in the end. Obviously, the answer is not that he regarded these questions as unscientific and meaningless. Rather, the solution lies in Carnap’s methodology and narrative, for he claimed that “[t]he individual no longer undertakes to erect in one bold stroke an entire system of philosophy. Rather, each works at his special place within the one unified science” (Preface to the Aufbau, xvi-xvii). In his autobiography, he remarked, “While I worked on many special problems, I was aware that this ultimate aim could not possibly be reached by one individual, but I took it as my task to give at least an outline of the total constitution and to show by partial solutions the nature of the method to be applied” (Carnap, 1963a, 16).

Carnap can be viewed as either a philosophically minded physicist and logician or a philosopher trained in the natural sciences. He certainly was not an art historian, a cultural and human scientist, or someone trained in the history of ideas, an individual someone typically finds studying geistige Gegenstände. As he stated, “unfortunately, a division of labor was necessary, and therefore I am compelled to leave the detailed work in this direction [i.e., the analysis of the social and cultural roots of philosophical movements, A.T.T.] to philosophically interested sociologists and sociologically trained philosophers” (Carnap, 1963b, 868). His only commitment was to the claim that geistige Gegenstände could be integrated into the scientific system of the Aufbau, and therefore, they earned the right to be included in the domain of the sciences. Carnap attempted to demonstrate the transcendental conditions geistige Gegenstände must meet to be considered suitable candidates for knowledge. However, he left the task of working out a detailed system of their constitution to others.

4 Geistige Gegenstände in the Context of Freyer’s Theorie

Freyer’s (1923) Theorie des Objektiven Geistes – Eine Einleitung in die Kulturphilosophie (Theory of Objective Mind – An Introduction to the Philosophy of Culture) is of crucial importance for understanding the sections of Carnap’s Aufbau discussed above. In Theorie, Freyer aimed to show that the human and cultural sciences are concerned with those objects that are the products of the mind; such products are the objective, or better, objectivised mind (Geist). Through the various cultural and human-made (geistige) objects, a “mind stands face-to-face, over time and space, with another mind” (Freyer, 1998, 1). One of the main tasks Freyer addressed was to analyse and describe the logical structure of the connections between human cognition and action, which create objectivations that become a separate and autonomous field of knowledge and domain of objects. These objectivations are manifestations of the cognition and the cultural/geistige objects. After passing through the various layers of objectivation, geistige Gegenstände solidify and become documents of the human cultural world. In the next few paragraphs, I discuss several texts and contexts that exemplify the importance of Freyer for Carnap’s Aufbau.Footnote 33

Although the first edition of Freyer’s Theorie appeared in 1923, it can be read as a counterpart to Carnap’s planned Aufbau project that later became the actual Aufbau. It should be mentioned at the outset that Freyer claimed his task was no longer a theory of Kulturwissenschaften (cultural sciences), as it had been for the Southwest School of neo-Kantians, but a theory of the cultural world. In this respect, Freyer is much closer to the Dilthey School than to the neo-Kantians since his forbearance of “Kulturwissenschaften” goes hand-in-hand with his project in the “Geisteswissenschaften”. Freyer seems to claim that his philosophical investigations belong to the sphere of the human sciences as a foundational project termed the “philosophy of culture” (Kulturphilosophie), whose main interest is the “formation of the historical world,” (Aufbau der geschichlichten Welt), just as in the case of Dilthey’s “Aufbau” from 1910.

While Freyer investigates the laws and objective structures found in the cultural world, he believes that the same type of investigation must be performed with respect to the other aspects of the world:

There is a logical parallel to those questions, which the philosophy of nature [Naturphilosophie, A.T.T.] formulates with respect to the universal composition [Aufbau] of the material world. […] Here, as there, the objective world, examined according to its composition, exists as an object of scientific research. […] To say this is naturally to say nothing against the possibility and the particular legitimacy of such a theory of objective structure: every science carries out this transcendental ‘reduction,’ this abstractive turn toward objectivity (Freyer, 1998, 10).

Just as it does in this passage from Freyer, objectivity (and intersubjectivity) played an important role in Carnap’s Aufbau.Footnote 34 Carnap and Freyer’s common project thus could be described as follows: one of the philosophers is interested in questions of the natural and physical world of experience and will show how we can constitute that world, while the other is interested in the human sciences and will show how we can render the cultural world within the broader conception of the natural world but with the same degree of objectivity. Another passage from the introduction to Theorie supports this interpretation:

The relation between the philosophy of culture and philosophy is actually one of a remarkable two-sidedness. Whoever thinks along the lines of the philosophy of culture must doubly arrange his work in the philosophical movement of the present. [T]he philosophy of culture is today merely an anticipation; […] it works with a logic that is still not developed. […] On the other hand […] it may hope that its results will reach far beyond the boundaries of its own formulation of the problem (Freyer, 1998, 14).

Despite the lack of evidence, it is safe to assume that the “logic that is still not developed,” which was in fact the logic of relations applied to the social sciences, was also pursued by Carnap. The new logic of relations was formulated by Bertrand Russell and Alfred North Whitehead (and earlier by Gottlob Frege). However, Russell and Whitehead’s Principia Mathematica, which codified their main results in the field, was either unavailable in Germany in the early 1920s or was too expensive because of the high inflation.Footnote 35 Thus, for Freyer, the details of this new logic and its possible applications in the various sciences were mediated, as we will see, through Carnap. (Although Frege could be mentioned as another source, if we consider the general neglect of Frege’s research and the fact that he did not consider applications of his method in the physical and social sciences, Carnap is a more plausible candidate.)

It is known that Carnap circulated among his friends certain mimeographs of the preliminary notes of what later became the Abriss der Logistik (1929) as early as 1922.Footnote 36 The Abriss was purported to be a shortened survey version of Principia Mathematica, emphasising in particular the possible applications of the logic of relations. Carnap stressed this character of his research to Schlick in a letter on 7 October 1927: “My main purpose is to present the Logistic [Logistik] as such a method which could be used in the various (non-logical) fields” (RC 029–31-06). Assuming that Freyer knew of Carnap’s (1929, §39) intention to develop an account of how to use the logic of relations in the various sciences through the constitutional system, he could have referred to it.

There is also textual evidence in Freyer’s work where he claims that “[t]he task of such a logic would be to formulate a theory of those concepts that are not classificatory concepts” (Freyer, 1998, 143), i.e., relational concepts. Carnap also mentions this question in the Aufbau.Footnote 37 The relevant passage is as follows:

Recently (in connection with ideas of Dilthey, Windelband, Rickert), a “logic of individuality” has repeatedly been demanded; what is desired here is a method which allows a conceptual comprehension of, and does justice to, the peculiarity not [emphasis mine, A.T.T.] through inclusion in narrower and narrower classes. Such a method would be of great importance for individual psychology and for all cultural sciences, especially history. (Cf., for example, Freyer [Obj. Geist] 108f.). I merely wish to mention in passing that the concept of structure as it occurs in the theory of relations would form a suitable basis for such a method. The method would have to be developed through adaption of the tools of relation theory to the specific area in question (Aufbau, §12, translation modified).

Carnap states here that all the scholars he mentions require a tool for “conceptual comprehension” (begriffliche Bearbeitung), which will be useful for individual psychology (often used and referred to by Freyer) and the cultural sciences. However, the passage also applies to the human sciences. In the original English translation, the passage reads that “what is desired here is a method which allows a conceptual comprehension of, and does justice to, the peculiarity through inclusion in narrower and narrower classes,” thus indicating that Carnap is concerned with the old classificatory concepts against which Freyer raised concern. In the German text, however, we find that Carnap requires that the method should not be applied through inclusion in narrower and narrower classes but should utilise structural and relational concepts. These structural and relational concepts might form a more “suitable basis” for that task (a view shared by Freyer and others).Footnote 38

In the paragraph cited above, Carnap refers to a passage from Freyer in which the latter discusses the problems of the connections between individual psyches and nations. Freyer claimed that simple categorical concepts and logic treat nations as “mystical unitary objects” (Freyer, 1998, 112–114) and thus cannot recognise their individuality. They interpret them as masses and elucidate them schematically. What Freyer desired was a clearly articulated conception of structures because the “psychic structure of every human being” is the basis for constituting “his own area of life and creative activity” (Freyer, 1998, 113), which sets up the nation and society. A logic with simple subject–predicate forms (such as syllogisms and the “old logic”) handles such items as one element, one subject (a value of a constant, for example), while an adequate approach would treat them as something that should be understood via various relations and structures inherent in and present between them. From this viewpoint, one could state that society is not a subject—i.e., a value of a constant—but is consists of many individuals and the various relations among them.

Although Carnap referred to his Abriss der Logistik, he also admitted that in that book he had not worked out the application of the theory of relations to the cultural and human sciences (Aufbau, §12). In the Abriss, he expounded the formal part of his constitutional theory and demonstrated that in this system, all autopsychological, physical, heteropsychological, geistige and cultural objects could be constituted. He also addressed the question of temporal objects (zeitbestimmte Gegenstände) such as psyches, but one could also include here nations, cults, institutions and other products of the human mind.Footnote 39

Similar to Carnap, Freyer also framed his investigations in a Kantian-transcendental manner. While Carnap asked, “how is objective knowledge possible,” Freyer (1998, 1, 5) raised the question of what makes the human sciences and the knowledge produced by them possible at all: “It should be asked of the philosophy of culture what are the elements and the conditions for the fact of objective mind” (Freyer, 1998, 28). Freyer’s answer to this transcendental question consisted of the observation that the philosophy of culture and the human sciences are concerned with problems and material that connect humanity across space and time:

In these expressions [e.g., products from ancient times, A.T.T.] lived kindred beings [Wesen]: we read what they have written; we see what they have painted; we find what they have built. [A] mind now stands face to face, over time and space, with another mind. If both minds do not resemble one another in their fundamental structure [emphasis mine, A.T.T.], then no understanding would take place: the commonality of human nature in its essential composition [wesentlicher Bau], both present and past, is the prerequisite for the understanding of the human sciences (Freyer, 1998, 1).

The common structure of mind (Geist) serves as the basis for understanding (verstehen) cultural achievements through their objectivation in the (cultural) world. Thus, structures play a constitutive role in our knowledge formation processes. Freyer’s epistemological insights indicate further striking features that can be found later in Carnap’s work. One such feature is the multi-layered theory of knowledge and the idea of a constitutional (“Aufbau”) system. According to Freyer,

[w]hen we undertook to understand a concrete meaningful content, it appeared necessary to comprehend that content as a framework of several layers [emphasis mine, A.T.T.]. It is understood that these layers are products of abstraction [emphasis mine, A.T.T.]. The actual structure contains its entire meaning in a firmly bound unity; living understanding gets hold of it without division – only hermeneutic theory is compelled to dissect the complex into a system of layers. […] Thus, every piece of objective mind, wonderfully expressive and wonderfully concealed, bears a multilayered meaningful content [emphasis mine, A.T.T.] (Freyer, 1998, 116f.).

Before turning to the theory of knowledge, it should be noted that Freyer seems to take the side of what Carnap later termed “rational reconstruction.” Although Freyer refers to this as “hermeneutics” (a legacy of Dilthey’s work), the ideas are quite similar. Freyer claims that the contents and elements of our knowledge are constituted (he is using the concept of “Aufbau” in this context) in different layers, but originally it is a “firmly bound unity.” Therefore, it is the task of the human scientist to dismantle this unity into its various layers and structures. As Carnap later put it in Aufbau, “intuitive understanding is replaced by discursive reasoning.”Footnote 40

Freyer invests a considerable amount of time in uncovering the different layers and modes of the objectivation of mind, i.e., the meaningful contents and activities of the subject that are placed in the cultural world.Footnote 41 By considering this point, one can gain insight into Freyer’s general approach and investigatory methods. Such analyses were not performed in detail by Carnap. However, he noted that a thorough analysis would require such considerations. In his diaries, Carnap emphasised that it was essential for him to talk with Freyer about these issues. On 1 October 1923, he noted, “Reading now frequently Freyer’s Objective Mind providing it with rich marginal notes; wish he was here; we would have so much to discuss! Particularly interested in mapping the relation of different spheres of activity to another (formation of complexes) [Komplexbildung]” (RC 025–07-02).

Freyer identified three modes of objectivation. On the first level are the so-called representative and expressive gestures, such as the clenching of fists or the stretching out of an index finger pointing to a book; in these cases, “the object of the gesture [e.g., rage] is not indicated in the gesture itself, what is indicated is the frame of mind” (Freyer, 1998, 21). Here, a thought, a feeling, an intention is objectivated in the form of clenching and stretching. Thus, to understand intentions we must recognise their objectivation, through which we have access to the (mental) states of others. Also on the first level are the expressing gestures that express the psychic condition of the subject through the qualities of the speaking voice (tempo, sound) or gestures. They are more complex than simple finger-pointing. However, they are interconnected: it is much easier to understand finger-pointing or fist-clenching when we know the agent’s psychic condition.

The second level of objectivation yields forms that are congealed signs. While pointing somewhere in the room, the motion of my arm objectives my psychic condition, which is the intention of calling the attention of others to something; this is the first objectivation. In addition, it becomes a sign of direction, which is the second objectivation. Pointing can adopt various modes and occur in different ways, but “irrespective of how the gesture is carried out, it signifies the same thing” (Freyer, 1998, 30) and can also be instantiated in different contexts: if you point to the Antarctic, you always point to the south (of course in a given and fixed framework of symbols and meanings).

Finally, there is the most complex form of objectivation. “The representative gesture can leave lasting traces of greater or lesser performance in the framework of the objective world” (Freyer, 1998, 31). When I point to the south, my pointing is only the image of a momentary gesture extended in time. However, images may become stable. In the case of a signpost, for instance, “the transitory gesture is solidified, materialized: it has been objectified in a third sense” (Freyer, 1998, 31). The distinguishing feature of the third layer is the materialisation, or physicalisation, of the psyche. Pointing in a single direction is one thing. Watching the pointing until it stops is another. However, confronting a directing sign from an ancient culture, i.e., another time and space, in the present is yet another. As Freyer states, “The third step consists in the sign, the external bearer of meaning, being lifted out the flow of the performing action and being solidified into a lasting condition” (Freyer, 1998, 32).

Before turning to the question of the relations between these objectivated forms and the mind, I shall mention another layered structure of the Theorie. Freyer (1928/1998, 158) differentiates between three systems of culture that “shade […] on the top of another according to the degree and type of tension between life and form that is established in those systems.” The first layer contains language, myths, cults, customs, and economics. Their existence depends on the community who believes in them; thus, the connection between life and form is the most obvious and close on this level. The second layer of cultural/geistige objects includes art, science, and law, which are detached from the creative subjects; they are materialised into physical products. The third, the most complex layer, consists only of the state (Staat).

It may be expected that in the Aufbau’s relevant passages (§§150–151), one would encounter precisely these structures or at least highly similar ones. This is not the case. The situation is rather complicated. Carnap marks two general categories: primary and higher geistige Gegenstände. The former category includes those objects whose constitution requires only the manifestation relation; i.e., they are directly observable through their manifestation. “It is the task of a logic of the human sciences to investigate which objects of the various cultural areas [Kulturgebiete] are to be constituted as primary geistige Gegenstände” (Aufbau, §150). Since Carnap’s preliminary example of a concrete constitution is the custom of hat-lifting, it is plausible to suppose that Carnap’s primary objects correspond to Freyer’s first layer of cultural systems inasmuch as the existence of customs depends on the community.

The objects of Freyer’s second layer are detached from the human community, and as he claimed, “the bearers of a style” (Freyer, 1998, 159), as are art, science, and law. Although art, science, and law are also geistige Gegenstände for Carnap, he did not explicitly include them among the higher ones. The higher geistige Gegenstände “are constituted on the basis of the primary geistige Gegenstände, but psychological, and occasionally physical, objects are also used” (§151). In this sense, the constitution of a physical object, such as an artwork or scientific outcome (i.e., a geistiger Gegenstand) requires the psychological behaviour and dispositions (i.e., further geistige Gegenstände) of the artists and scientists (for example, their intention to produce art and science) and the relevant cultural and social connections.

So far, so good. Carnap’s higher geistige Gegenstände seems to correspond to Freyer’s second level. However, here come the differences. Among higher geistige Gegenstände, Carnap mentioned the state (§151) and other sociological groups, such as families, tribes, and clubs. The state was the most complex cultural system in Freyer’s concept and constituted its entire third level. From Freyerʼs perspective, the other sociological groups mentioned by Carnap belong to the first level; for example, the existence of a tribe depends on the members of the tribe.

Two considerations must be mentioned here. At first, Carnap affirms it is the task of the human sciences to classify and order the geistige Gegenstände. Therefore, his considerations are only suggestions. What is interesting is that Carnap, at this point, only mentions Hans Driesch as a point of reference (§151), whereas Freyer had already recommended such classifications and structuring, and Carnap had to have been aware of them. As I have mentioned, Carnap read Freyer’s Theorie several times, and they also discussed Carnap’s “structure thesis” (Strukturthese) and the “conception of the state [Staat] through psychical acts” (RC 025–72-02), as Carnap noted in his diary on 25 October 1925. Carnap also attended a lecture by Freyer at the University of Kiel on the topic of Kultur und Staat (“Culture and the state”)Footnote 42; all of these indications imply that Carnap should have known about how human scientists classify (and constitute) geistige Gegenstände.

When accounting for our knowledge of cultural objects, Carnap relied on manifestation and documentation relations. Freyer also held that these relations were fundamentally important for the human sciences. He claimed there are various objectivated forms of mind that are not exhausted by their physical objectivation but only manifest them. Carnap’s example was hat-lifting, which he seems to have adopted from Freyerʼs Theorie. “[T]he community exists not merely in the lived experiences and expressions of the feeling of belonging together,” maintained Freyer, “but it becomes a social body that persists in its specific form, while individuals enter into it and leave it, actually participating in it or not” (Freyer, 1998, 66). What matters in most cases are, somehow anachronistically, the dispositions, because geistige Gegenstände “transcend the actions and are only carried out in them” (Freyer, 1998, 19). Actions merely manifest geistige Gegenstände (cf. Freyer 1928/1998, 38, 52), as, for example, the speed and volume of the speaking voice manifest the inner psyche. These manifestations are only momentary objectivations and occur on the first layer of the aforementioned structure of objectivation. However, geistige Gegenstände can also assume lasting forms when they become materialised:

Physics and chemistry investigate stone as a material composition. However, what makes this stone into a document [emphasis mine, A.T.T.] of humanity is that ages ago, a couple of crude blows shaped it into a hammer. […] In this case, a psychic meaning appears through its material, and thus, apperceived in this way the stone has all at once developed from an object of mineralogy into an object of the human sciences (Freyer, 1998, 1).

The lasting physical objects do not manifest the background creative mind whose mental life is materialised in the object but document it. Freyer takes it for granted that “human mind has been realised in […] arrangements of the physical world and now dwells within this material housing” (Freyer, 1998, 17). These physical objects are occasionally from earlier times, and one does not have direct access to the background of the acting subjects from those times. The only access available is the documents that were produced by creative minds.

Both in the Aufbau and in the Theorie, knowledge and understanding spring from the physical and material manifestation of geistige Gegenstände. Even if our methodology is based on the Diltheyian concept of understanding (Verstehen) (and later the ideas of others who somehow distorted the original conception), we must first recognise those physical entities within which the objective mind “dwells.” Therefore, if we wish to rationally or hermeneutically reconstruct the structure and means of our knowledge of them, we must start from the physical, material, and objective world. Thus, from Freyer and Carnap’s perspective, this task is for natural scientists and, above all, philosophers. It is philosophers who must provide logical frameworks and concepts suitable to analysing both the natural and cultural worlds. As Freyer states:

All thinking, especially that of the sciences of life, of the psyche, and of the mind form such [relational] concepts – only philosophy still has to pay a debt to the new logic which must establish the law and the right of such conceptual formation. […] That it should be accomplished is a pressing necessity; the consolidation of our entire scientific thought, its purification from all kinds of impure mysticism, and its effect on life depend on it. That it should be done soon is, for many, a hope; for us, a certainty. Ave, philosopher! (Freyer, 1998, 143).

Carnap must have been intrigued by these words. He became just one such philosopher who tried to work out the application of the new logic to the problems and issues of the entire phenomenon of scientific thought, sought to purify science of all types of impure mysticism, and tried to show in the Aufbau project the effect of scientific thinking on life.Footnote 43

5 Summary

In this essay, I have focused on a still neglected aspect of the Aufbau: the constitution of geistige Gegenstände and its connection to the Dilthey School via the influence of Hans Freyer. Earlier, Alan Richardson suggested that

[t]he Russellian perspective [of the Aufbau] fails to engage with the text of the Aufbau in anything like its own terms. [Carnap’s] problem itself and the role of formal notions in its solution, combined with indubitable facts about the sort of philosophical education Carnap received in the 1910s in Jena, reorient the story toward a rather different philosophical tradition from Russell’s – the tradition of scientific neo-Kantians (Richardson, 1998, 1f).

Considering Freyer’s role in Carnap’s formative years and early intellectual development, one could rephrase Richardson’s remarks as follows: The British, Austrian and certain elements of the German perspectives fail to engage with the text of the Aufbau on anything like its own terms. Carnap’s problem itself and the role of notions in its solution combined with the indubitable facts regarding the type of philosophical education Carnap received and the intellectual background he developed in the 1910s in Jena, in the Serakreis, later in Freiburg, and in the numerous meetings and workshops in which he participated in Germany reorient the story towards a rather different philosophical tradition from that to Russell, Mach and the neo-Kantians belong, namely, the tradition of Geisteswissenschaften.

This tradition was in full bloom in Jena (in the Serakreis) and Freiburg in the first quarter of the twentieth century. The thinkers principally associated with the Dilthey School are Herman Nohl, Franz Roh, Wilhelm Flitner, and Hans Freyer. Consequently, one should draw the conclusion that given the impact of Freyer and the so-called Dilthey School, the German roots of Carnap’s Aufbau reach deeper than previously thought to be the case.