Psychology is still a very young science and in a particular way and very prematurely fragmented into schools, which has meant that psychology 'will probably never be unified under a single, coherent and rigorous theoretical framework'. Christopher D. Green, 'Why Psychology isn't Unified, and Probably Never Will Be'. Review of General Psychology 19, no. 3 (2015): 208. https://doi.org/10.1037/gpr0000051. ¹ Indeed, modern psychology has in Wilhelm Wundt and Sigmund Freud the founders of the most important schools of psychology, namely experimental psychology, and psychoanalysis respectively. The importance of the pair Wundt and Freud in psychology is equivalent to Karl Marx and David Ricardo in economics or Charles Darwin and Herbert Spencer in biology. Certainly, historiography has in the past been responsible for forging an image of radical antagonism between Freud and Wundt, then this has begun to be nuanced in recent work such as that published by Gordana Jovanocić who sees that Wundt's introduction of unconscious mental processes bears certain similarities to Freud's justification for assuming the existence of the unconscious. Gordana Jovanocić, "A Revival of Wundt's Heritage: Searching for the Philosophical Foundations of Psychology from an hisTorical Perspective". Theory & Psychology 28, num. 6 (2018): 847-854.https://doi.org/10.1177/0959354318763116. ² It is striking that there has never been a study of mutual influences through quotations from the works of both because being contemporaries as it will be seen below, they could not have been indifferent to each other's work. The reluctance to study the relationship between the two works may be a consequence of the fragmentation of psychology into different schools that have generally been considered as 'closed systems, 'quite impervious to extraneous influences and to evidence contrary to their conceptual framework'. See Rubén Ardila, 'La necesidad de unificar la psicología: el paradigma de la síntesis experimental del comportamiento', Revista Colombiana de Psicología, no. 12 (2003): 34. ³

The opposition between psychoanalysis and experimental psychology was not so evident at the beginning, precisely the disciples of Wundt and Freud were the first to point out and describe a certain relationship between the two schools, namely the psychology of normal consciousness as opposed to the psychology of the unconscious or of pathological/abnormal consciousness, as is evident in the text The Message of the Zeitgeist by Granville Stanley-Hall, Granville. “The Message of the Zeitgeist”. 13, núm. 2 (1921): 106-116. Stanley Hall (1921). The latter, however, does not oppose both schools; on the contrary, he sees them as fields that in the future could collaborate, given that the object of research was different but not opposed. Another example of this affable relationship was Carl Jung who often quoted Wundt in his experiments in the Zurich clinic. However, a sort of animosity begins to show in texts such as 'A Criticism of psychoanalysis' of 1914, in which he describes the climate of criticism of the idea of the unconscious and makes a forceful parting of the waters,

Here the author states that inspired by Wundt's critique of the unconscious, American psychologists, most of them disciples of Wundt himself, opposed the Freudian unconscious based on the concept of 'Scheinerklarung', while European psychologists and psychiatrists had comfortably assimilated it. Lev Vygotsky in his famous text 'Istorícheskii smysl psijologuícheskogo krízisa [the historical significance of the crisis of psychology]' (1927) emphasized more strongly this position in which Wundt was antagonistic to the idea of the unconscious as an 'echo of the mystical naturalistic naturalistic philosophy of the early 19th century'. The idea of the unconscious or better still its ontological status is situated as the philosophical element that would definitively divide Freud and Wundt, but which cannot be explained simply as antagonistic. This article argues for establishing that between the two modern thinkers and psychologists there may have been something more than an antagonistic relationship, their works show that some ideas were more or less willingly received in the case of Freud while in the case of Wundt the idea of the unconscious always appeared to him as a danger and he recoiled from any hint that might contradict his psychological system.

Wilhelm Wundt (1833-1920) and Sigmund Freud (1856-1939) are usually regarded as leading figures in modern psychological thought, the former being recognised as the founder of experimental psychology and the latter as the funder of psychoanalysis. Kurt Danziger, 'Wilhelm Wundt and the Emergence of Experimental Psychology', in Companion to the History of Modern Science, ed. R. C. Olby, G. N. Cantor, J. R. R. Christie y M. J. S. Hodge (London & New York: Routledge, 1996): 396-409. ⁵ Although Wundt was 24 years older than Freud, both were influenced by the revolution in the field of life sciences [Naturwissenchaften], modern physiology, anatomy, neuropathology among other sciences that developed since the mid-19th century. Arthur Blumenthal, 'Wilhelm Wundt: Psychology as the Propaedeutic Science', in Points of View in the Modern History of Psychology, ed. Claude E. Buxton (Florida, Academic Press, 1985): 19-47; Vanessa Lemm, 'Deconstructing the human: Ludwig Binswanger on Homo Natura in Nietzsche and Freud', in Nietzsche an the Antichrist. Religion, Politics and culture in Late Modernity, ed. Daniel Conway (New York: NY, Bloomsbury Academic, 2019): 205-228. ⁶ The classical period of German physiology was a great influence on Wundt and Freud. Wundt's early years of medical training were under the tutelage of Friedrich Arnold (1803-1890), a professor of anatomy and physiology who worked in University of Tübingen and University of Heidelberg. Saulo De Freitas Araujo, Wundt and the Philosophical Foundations of Psychology: A Reappraisal (Springer, 2016). ⁷ In 1854, Wundt conducted research at home on the effects on respiration after sectioning the vagus and recurrent nerves in rabbits and resulted an article resulting from this research was published in the Archiv für Anatomie, Physiologie und wissenschaftliche Medicin (1834-1876) edited by the German physiologist Johannes Müller. Solomon Diamond, 'Wundt Before Leipzig', in Wilhelm Wundt in History. Path in Psychology, ed. R.W. Rieber., D.K. Robinson (Boston: Springer, 2001): 1-68; Herb Simonsz, 'Johannes Peter Müller's first description of the relation between accommodation and vergence, and of accommodative esotropia in 1826', Strabismus, 18, no. 1 (2010): 1-2; Claudia Wassmann, 'Physiological optics, cognition and emotion: a novel look at the early work of Wilhelm Wundt', Journal of the History of Medicine and Allied Sciences, 64 (2009): 213-249. ⁸

In the same way of Wundt, Freud joined to the physiology laboratory of Ernst Wilhelm von Brücke (1819-1892) in his third year of medicine and developed a work in the field of anatomy, specifically on the histology of the nerve cells of the fluvial crayfish. Ernest Jones, Vida y obra de Sigmund Freud. Tomo I [Life and Work of Sigmund Freud. Volume I] (Barcelona: Editorial Anagrama, 1981). ⁹ Brücke was considered in Berlin as the 'ambassador to the Far East' of the classical period of physiological research in Germany (klassische Periode physiologischer Forschung). Heinrich Boruttau, Emil du Bois-Reymond (Leipzig: Rikola Verlag, 1922). ¹⁰ The Berlin School developed the physiology under the principle that the progress of life and in general of all organisms reduced to two forces: attraction and repulsion. Karl J. Fink, 'Actio in Distans, Repulsion, Attraction: The Origin of an Eighteenth Century Fiction', Archiv für Begriffsgeschichte 25, num. 1 (1982): 69-87. ¹¹ This physiology principle was a great influence for Freud, as he told to Ernst Jones in 1926 was the theorical influence of the dynamic aspect of psychoanalysis, 'forces help or inhibit each other, combine with each other, enter into engagement with each other'. Ernest Jones, Vida y obra de Sigmund Freud. Tomo I [Life and Work of Sigmund Freud. Volume I] (Barcelona: Editorial Anagrama, 1981), 65. ¹² The fact that Wundt dissociated from the Helmholtz school and in general from the most significant figures of Berlin physiology, made it impossible for him to have an early meeting with Freud, who had an outstanding work on histology in ganglion cells. Siegfried Bernfeld, 'Freud's earliest theories and the school of Helmholtz', The Psychoanalytic Quarterly, 13 (1944): 341-362. ¹³ Wundt wrote in his autobiography that the work in the laboratory with Helmholtz was rather routine and completely devoted to electrophysiological research, but his really interests was on sensory physiology, which according to Helmholtz's criteria made it 'dangerously close' to physiological philosophy. Steindór J. Erlingsson, 'From Haeckelian Monist to Anti-haeckelian Vitalist: The Transformation of the Icelandic naturalist Thorvaldur Thoroddsen (1855-1921)', Journal of the History of Biology 35 (2002): 443-470; David Kent Robinson, Wilhelm Wundt and the Establishment of Experimental Psychology, 1875-1914: The Context of a New Field of Scientific Research, Doctoral dissertation, University of California (1987). ¹⁴ Wundt always felt constrained to develop his philosophical readings and once he left Helmholtz's institute published his first book Physikalichen Axiome un ihre Beziehung zum Causalprincip [Physical Axioms and their Relation to the Causal Principle] (1866).

Wundt and Freud at the end of their training in medicine, had a small step in internal medicine, which produced a pause in their research training. When Wundt completed his training and passed his exams in 1856, decided to become an assistant in a ward for women mostly from a vulnerable social class at the University Hospital of Heidelberg which was run by the professor of anatomy Ewald Hasse (1810-1902). Wundt's stay at the hospital lasted about half a year, where his patients were in many cases women that suffered from a sensory paralysis as result of leg injuries. His stay in the hospital led him to formulate the problem of localization developed in the book titled Contributions to the Theory of Sensory Perception 'Beiträge zur Theorie der Sinneswahrnehmung' (1862). Also, Freud started in hospital practice in psychiatry under the German Hermann Nothnagel. Wolfgang G. Bringmann, 'Wundt in Heidelberg: 1845-1874', Canadian Psychological Review 6, no. 2 (1975): 124-129; Élisabeth Roudinesco, Freud en su tiempo y en el nuestro [Freud in his Time and in Ours] (Madrid: Debate, 2014). ¹⁵ Another academic phenomenon that impacted in both scholarship career was the rise of hypnotism in the late nineteenth century. The field of hypnosis was divided between the school of Charcot in the Salpetriere and the school of Bernheim in Nancy, Wundt stated in his text of 1892, that he was not in favor of any school. For Wundt, hypnosis postulates the existence of a second mysterious mind [Unletbmskein] leads to a case of pseudo-explanation in which a new term is introduced to explain the phenomenon and to leave things as they are,

In Hypnotismus und suggestion, Wundt cites the German translation made by Sigmund Freud in 1888 of Bernheim's work titled De la suggestion. Ibid. ¹⁷ The preface to the translation was made by Freud in the years when he was a follower of Charcot and therefore had a rather critical opinion of Bernheim. As Freud expressed in An Autobiographical Study, of hypnosis 'I only retaining my practice of requiring the patient to lie upon while I sat behind him, seeing him, but not seen myself'. Sigmund Freud, 'An Autobiographical Study', SE, 20 (1925), 28. ¹⁸ Freud consider that effects of hypnosis were suddenly erased when the personal relationship with the patient was clouded, in other words, the personal affective bond was more powerful than any cathartic work, and secondly, according to Bernheim's experiments, when the subject awoke from somnambulism, he forgot everything that had happened in that state. Elisabeth Fortineau, 'Bernheim face à Charcot et Freud. L'École de Nancy'. L'Information Psychiatrique61, num. 3 (1985): 413-420. ¹⁹ Freud separates from hypnosis for a very similar reason exposes by Wundt that saw the impossibility of conducting introspection in the state of hypnosis, in other words, the lack of access to the contents of consciousness. Frederic W. H Myers, 'Wundt on Hypnotism and Suggestion', Mind, 2 (1893): 95-101. ²⁰ Curiously, the reasons for which they distanced themselves from hypnosis are similar in some points, however, according to Wundt, psychoanalysis was never detached from this practice, and on the contrary, it would be its philosophical and practical basis.

Although in many cases they are seen as antagonistic thinkers, the former as the psychologist of consciousness while the latter as the founder of the psychology of the unconscious, it is hasty to pass judgment of such magnitude without considering what they thought of each other's work. To review the mutual influence between the two authors, we reviewed Wundt's cites in Freud's work and Freud's cites in Wundt's work. Psychoanalysis after The Interpretation of Dreams (1900) took a direction like the development of experimental psychology in Germany as many psychoanalytic schools were founded at the beginning of the 20th century as there were experimental psychology laboratories in the world during the last years of the 19th century. While the rise of psychoanalysis began, Wundt worked on the 10 volumes of the Völkerpsychologie between 1900 and 1920 which signified an 'intellectual turn' in his career as it was a field far removed from his experimental research. John Greenwood, 'Wundt, Völkerpsychologie, and experimental social psychology', History of Psychology6, num. 1 (2003): 70-88. ²¹ The only few mentions of Freud in Wundt's works are found in the third volume of the fifth and last re-edition of the Grundzüge der physiologischen psychologie that were published between 1908-1911. Edwing Boring, A History of Experimental Psychology (New York: The Century CO, 1929). ²² Only one of the three volumes of the last edition was translated into English by one of his most distinguished disciples and founder of American structuralist psychology, E. B. Titchener, so that Wundt's views on Freud have been inaccessible to most of the international academy. The third volume, according to the foreword written by Wilhelm Wundt himself, was the one that underwent major changes,

Freud does not cede too much prominence to Wundt in the antecedents in works like the history of psychoanalysis development in works like The History of the Psychoanalytic Movement (1914) or Introductory Lectures on Psychoanalysis, Sigmund Freud, 'The history of the psychoanalytic movement', SE, 14 (1914); Sigmund Freud, 'Introductory lectures on psychoanalysis', SE, 15 (1916-1917 [1915-1917]). ²⁴ but instead, this paper corroborated that exists some theoretical elements of Wundt used by Freud in some works of his first twenty years of psychoanalytic literature. On the other hand, some of Freud's mentions of Wundt give a clear indication of the rivalries existed between the two of the most important schools of psychological thought at the beginning of the twentieth century. A review of Freud's citations indicates that psychoanalysis differs on theoretical and methodological levels with experimental psychology. On the first point, Freud makes it clear that it is the lack of a parallax structure in Wundt that makes it impossible for him to alert us to the effects of the unconscious. On the second point, regarding methodological discrepancies, Freud accepts some of Wundt's theses, but he distrusts that the experimental method is the most adequate to arrive at significant results on the unveiling of phenomena of the human soul.

The thesis of this paper is that the relationship between the Freud and Wundt analize through the mutual citation shows a parallax structure, in other words, the co-existence of two perspectives in which the antinomy cannot be dialectically mediated or solved because they have no common element. Slavoj Žižek, The Parallax View (Short Circuits) (Cambridge: MA, MIT Press, 2006). ²⁵ The unique common element between the wundtian experimental psychology and psychoanalysis is the incapability of the first to recognize the unconscious as a necessary instance (ontological or hypothetical) to explain some mental phenomenon. For Wundt the psychoanalysis is an heir to the remnants of the studies of hypnosis, mystical philosophy and spiritualism that were popular in the late nineteenth century. While Freud considered experimental psychology as powerless to recognize in its own findings, the theoretical necessity of constructing a hypothetical instance such as the unconscious. Freud intuits that it is the very results of experimental psychology that show the ways by which progressing through them can lead to the other side of the surface as a Moebius strip indicates, 'if we progress far enough on one surface, all of a sudden we find ourselves on its reverse'. Slavoj Žižek, Everything You Always Wanted to Know about Lacan (But were Afraid to Ask Hitchcock) (London and New York: Verso, 1992), 227. ²⁶

The mutual influence approach together with other techniques such as co-citation or bibliographical coupling with respect to citations is an approach increasingly used in bibliometric and historical studies to have a complete representation of the position of an author in the academic networks or conceptual structure of an author's work. Some of the guiding questions included in the Citation context analysis model developed by Anderson and Lemken Marc H. Anderson y Russell K Lemken Citation context analysis as a method for conducting rigorous and impactful literature reviews. Organizational Research Methods (2020). ²⁷ (2020) were used to review the mutual influence between Freud and Wundt appear in their works:

1. What contents of Freud's and Wundt's works were quoted by them?

The 24 volumes of the 1981 seventh edition of The Standard Edition of the Complete Psychological Works of Sigmund Freud translated by James Strachey were reviewed. It was found that in 7 of those 24 volumes there was at least one mention of Wilhelm Wundt. On the other hand, we examined Wilhelm Wundt's works published in German from 1900 onwards and found that 3 works made at least one mention of Sigmund Freud. Two of Wundt's works in which Freud was mentioned were the reprints of the three volumes of the Grundzüge der physiologischen published between 1908 and 1911 by the Verlag von Wilhelm Engelmann editor with the help of Dr. Otto Klemm. The last quotation about Freud was found in the fifteenth edition of Grundrisse der psychologie (1922) published posthumously and edited by his son Max Wundt with the help of the German psychologist Wilhelm Wirth at the Alfred Köner Verlag.

The procedure was developed as described below. First, we reviewed Wundt's cites in Freud's complete works (Standard Edition) and the Freud´s cites in Wundt´s works. Second, we determined the argumentative reasons that led Freud to cite Wundt and vice versa according with the citation context of citing publications.

The citations were organized in three categories:

The Table 1 shows that the first Freud´s citation about Wundt referred to Physiologischen Psychologie Wundt, Grundzüe der Physiologischen. ²⁸ and the Völkerpsychologie Wilhelm Wundt, Völkerpsychologie Vol. 1 (Leipzig: Verlag von Wilhelm Engelmann, 1900). ²⁹ appeared in The Interpretation of Dreams (1900), The Psychopathology of Everyday Life (1901) and Introductory Lectures on Psychoanalysis (1916-1917 [1915-1917]).

Table 1

According to Table 1. The Grundzüge der physiologischen Psychologie is the most cited work of Wilhelm Wundt in the complete works of Sigmund Freud. The Völkerpsychologie Die Sprache Teil I is the cornerstone of The Psychopathology of Everyday life Sigmund Freud, 'The Psychopathology of everyday life', SE 6 (1901). ³⁰ (1901). While volume II of the Völkerpsychologie. Mythus und Religion Sigmund Freud, 'Psycho-analysis and the establishment of the facts in legal proceedings', SE 9 (1906). ³¹ (1906) was fundamental for the writings on anthropology, folklore and philology collected under the name Totem and Taboo and Other Works (1913). For Freud, the work of the Zurich psychoanalytic school led by Carl Jung and the work of Wundt are pioneers in these subject and inspirational sources 'it was from these two sources that I received the first stimulus for my own essays'. Sigmund Freud, 'Totem and Taboo', SE 13 (1913), xiii. ³²

According to Table 2. The appearance of references to Freud in Wundt's work occurs from the fifth and last editions of the first and third volumes of the Grundzüge der physiologischen psychologie published in 1908 and 1911 respectively. A mention of Freud's work also appeared in the fourteenth edition of the Grundriss der Psychologie in 1911. The Interpretation of Dreams [Traumdeutung] is Wundt's most cited work, just the work where Freud includes most of Wundt's references.

Table 2

At the end of An Outline of psychoanalysis, Freud affirmed that between psychoanalysis and philosophy there was some conflict over the psychic apparatus, 'Now it would seem as if this dispute between psychoanalysis and philosophy concerned only an insignificant question of definition - the question of whether the name 'psychic' should be applied to one or the other sequence of phenomena'. Sigmund Freud, 'An outline of Psycho-analysis', SE, 23 ([1938] 1940), 158. ⁷¹ In the same text, alluding to the psychology of consciousness, whose major representative was precisely Wundt and his school, although not explicitly named. Freud stated, 'In fact, however, this step has become of the highest significance While the psychology of consciousness never went beyond the broken sequences which obviously depended on something else, the other point of view, which held that the psychic is unconscious in itself, enables psychology to take its place as a natural science'. Ibidem. ⁷² Freud also uses Wundt in many cases to put in evidence the legitimacy of his 'discovery', thus his unconscious, the Freudian unconscious, is not the same 'unconscious' intuited by philosophers and/or psychologists of consciousness.

After reviewing the biographical elements of Wundt and Freud and the mutual cites can be concluded that their relationship has a parallax structure because the wundtian definition of unconscious belongs of his own system of psychology where this kind of instance is seeing like a metaphysical while the Freudian approach of unconscious belongs of the natural sciences. Paul Assoun-Laurent, Introducción a la epistemología freudiana [Introduction to Freudian Epistemology] (Buenos Aires: Siglo XXI Editores, 1981); Adolf Grünbaum, 'Eine zusammenfassende Darstellung von die Grundlagen der Psychoanalyse: Eine philosophische Kritik', In Kritische Betrachtungen zur Psychoanalyse Adolf Grünbaums 'Grundlagen' in der Diskussion, Adolf Grünbaum ed (1991) (Budapest, Springer: 3-34. ⁷³ Wundt affirmed that the object of study of experimental psychology should move away from the metaphysical problems of philosophy and was not the same of the natural sciences because they prevented to scientific psychology raise his own problems. Saulo De Freitas Araujo, Wundt and the Philosophical Foundations of Psychology: A Reappraisal (Springer, 2016); Wilhelm Wundt, Outlines of Psychology (Leipzig: Verlag von Wilhelm Engelmann, 1902). ⁷⁴ In contrast, in 1938 Freud declared that the psychoanalysis 'is also a natural science' [Die Psychologie ist auch eine Naturwissenschaft], in other words, psychoanalysis had its origin and would have its future in the sciences of nature. Johannes Biehler, 'Freud et les sciences de la nature (Naturwissenschaften)', Wißbegierde et structuration psychique, Section I et II (2006). s.p. ⁷⁵ Clearly, psychoanalysis creates the unconscious as a thing that persists beyond the death sentence that experimental psychology passed on any hint of mysticism or transcendental philosophy that might exist in the treatment of psychic phenomena. The Freudian unconscious acts as a ghost resulting from the failure of the Project of experimental psychology, Wundt himself indicates the modest help that it presents to the knowledge of sick consciousness or non-normal stages of consciousness present in the third volume of the last re-edition of Grundzüge der physiologischen psychologie (1911).

Freud's inclusion in the last revised part of Wundt's Grundzüge der physiologischen psychologie shows the impossibility of closing his own system of thought, that some of the proposed categories show a lack and give way to the need to recognize again a remainder that had been denied in his doctrine, as evidenced in his rejection of hypnosis,

The parallax structure between Wundt and Freud is palpable in that both place their objects of research on different theoretical planes, different positions that they took derived from the 'quarrel of methods' (Methodenstreit), which arose from the rise of the so-called human or spirit sciences and their criticism of the sciences of nature and led to the division of the scientific community between the sciences of nature (Naturwissenchaften) and the sciences of the spirit (Geiteswissenschaften). Vinicio Busacchi, 'Lacan's Epistemic Role in Ricœur's Re-Reading of Freud' Ricoeur Studies/Etudes Ricoeuriennes 7, num. 1 (2016): 56-71; Christian Stadler, 'Aufstellungsarbeit von Träumen', in Praxishandbuch Aufstellungsarbeit. Grundlagen, methodik und anwendungsgebiete, 461-475. C. Stadler and B. Kress eds. (Wiesbaden: Springer, 2020). ⁷⁷ Freud claimed a place for the psychoanalysis in the natural sciences, 'Freud uses the same vocabulary as Haeckel in everything he says (in relation to the humanities)' and is 'influenced by the anti-dualist culture of physicists, physiologists, German psychologists and the empiricism of John Stuart Mill'. Assoun-Laurent, Introducción a la epistemología freudiana; Grünbaum, 'Eine zusammenfassende Darstellung…'. ⁷⁸ As noted in the article, the major point of relationship of Wundt and Freud occurs in the book The Interpretation of Dream, which contrary to what authors such as Ricoeur Paul Ricoeur, Freud and Philosophy. An Essay on Interpretation (New Heaven and London: Yale University Press, 1970). ⁷⁹ (1970) who asserted that this work brought psychoanalysis into the field of hermeneutic sciences; this work does not change its belonging to the natural sciences and this is palpable insofar as Freud cites as antecedents to his theory of dream formation authors from physiology, among whom he cites Wundt. Precisely Freud's doctrine of dream formation is a continuation of a problem that Wundt could not develop, as was shown in the article, as a consequence of the theoretical restrictions that his model designated for him. The interpretation of the dream that often stands out on the hermeneutic side, its explanation never brs with a causal and explanatory deterministic structure; this is how Freudian dream interpretation always leads to an explanation as it does in the natural sciences.

This article showed for the first time the mutual influences between the works of Wundt and Freud and it was found that the relationship of antagonism is the product of a superficial and prejudiced reading of both. The best way to prove the contrary was to refer to reading directly what each had said about the other in the strictly academic field. This fact leads us to the need to examine the existing and past psychological projects in search of the true elements that differentiate them from each other precisely because the search for psychology to be a science must necessarily be based on solid and clearly defined conceptual, epistemological, and methodological foundations. This article aimed to find a 'philosophical explanation of a historical event' in this case the historical separation of both psychological systems (Fierro & de Freitas-Araujo, 2020). Catriel Fierro y Saulo Araujo de Freitas, 'A Case for a Philosophical History of Psychology: An Interview with Saulo de Freitas Araujo at the Centenary of the Death of Wilhelm Wundt'. Human Arenas, núm. 4 (2021): 64-73. https://doi.org/10.1007/s42087-020-00165-z ⁸⁰