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© 2024. All rights reserved.
Site created with
Hakyll.
Modified theme
lanyon-hakyll
based on
Lanyon.
Rasmus Nielsen 1809-1884 was an incredibly productive philosopher who was professor at the University of Copenhagen for forty years. (For chronological orientation: Rasmus Nielsen died the year before Niels Bohr was born.) He seems also to have been extremely popular, both among his students and among the public at large. But after his death in 1884, his influence quickly waned, and he was basically forgotten.1
For the most part, we can only speculate about why Nielsen so quickly fell out of favor. I think his fall has two related causes. First, during the “battle over faith and reason” in the 1860s, Nielsen ended up looking pretty silly in comparison to the young intellectuals such as Georg Brandes. Second, Nielsen’s entire philosophy was focused on showing why God’s existence is a necessary presupposition for scientific knowledge. Since Denmark was rapidly secularizing in the late 19th century, it’s not surprising that the younger generation simply lost interest in Nielsen’s philosophy.2
We will argue that Rasmus Nielsen’s philosophy is a key part of the background to Niels Bohr’s thought. Our argument for this claim has two components. First, and externally, there is a lot of circumstantial evidence pointing to a connection between Nielsen and Bohr. Second, and internally, there are several aspects of Nielsen’s view that are suggestively close to things that Niels Bohr said.
Up until the 1960s, every student at the University of Copenhagen took the year long philosophy course called Filosofikum. As a result, all Danish intellectuals had a common body of knowledge of the philosophical tradition, and a common set of standards for philosophical discussion. What’s more, a single professor — such as Rasmus Nielsen — had a large influence on the philosophical mindset of the entire educated population.
Nielsen started teaching Filosofikum in the 1840s, and alternating with Frederik Sibbern, he taught the course into the late 1870s. We still have access to his lecture notes from many of these courses, and we also have access to some of the notes that the students took in the classes.3 We also know many of the students who took the course under Nielsen, and it’s a veritable who’s who of Danish intellectuals.
Here are some of the students who we know took Filosofikum with Rasmus Nielsen:
It is well-established that Bohr read some Kierkegaard. Nonetheless, we agree with other scholars that Bohr wouldn’t have nodded his head and said, “yes, I agree with Kierkegaard.” The problem is that Kierkegaard’s worldview was too different from Bohr’s — too focused on the God-human relationship, sin, redemption, etc. And Kierkegaard doesn’t seem to say anything of relevant to the practice of science. So, it would seem misguided to look for a direct influence of Kierkegaard on Bohr.
That leaves open the question of whether there might have been an indirect influence of Kierkegaard on Bohr. Could Kierkegaard have influenced a mindset that Bohr himself inherited? Recall that Bohr was a student at the University of Copenhagen fifty years after Kierkegaard died. What were the philosophical trends in Copenhagen when Bohr was a student? It certainly wasn’t trendy to be a Hegelian, as it was at Cambridge, as Hegel’s philosophy had never really found a receptive audience in Denmark. There might have been some hints of neo-Kantianism, which was popular at that time in neighboring Germany. But there was no neo-Kantian professor at the University of Copenhagen.
In short, none of the “major” philosophical traditions (i.e. traditions that one reads about at American universities) was ascendant in Denmark when Niels Bohr was a student. Not British empiricism, nor continental rationalism, nor their Kantian synthesis, nor the Hegelian resolution of Kantian subjectivity. As of 1905, philosophy in Denmark was Harald Høffding, and Høffding was eclectic.
Despite his eclecticism, Høffding was profoundly influenced by his reading of Kierkegaard.4
In the 1830s, Hegelianism was in the air at the University of Copenhagen. The newly appointed professor of theology, Hans Lassen Martensen, was a right-wing Hegelian; and the prominent author, Johan Ludvig Heiberg, explicitly adopted a Hegelian viewpoint. It’s not surprising then, that students like Rasmus Nielsen would follow suit, and his earliest work was explicitly Hegelian.
Nielsen overlapped at the University of Copenhagen with Søren Kierkegaard. In fact, we know from Kierkegaard’s journal entries that they were acquaintances — and that Kierkegaard didn’t have all that high an opinion of him. While Kierkegaard dawdled as a student, and never got an academic job, Nielsen quickly finished his degrees, and was appointed professor of philosophy at the University of Copenhagen. (Nielsen got the chair that had been held by Poul Martin Møller until his death in 1838.)
In the mid 1840s, Kierkegaard launched his attack on Hegel, with publication of the Concluding Unscientific Postscript in 1846. Rasmus Nielsen was immediately convinced of the correctness of Kierkegaard’s point of view, and he sought out Kierkegaard for further discussion. They had a rather close relationship for a couple of years, until Kierkegaard was put off by the way that Nielsen was publicizing his views. Their relationship cooled off, but Nielsen continued to work with an explicitly Kierkegaardian approach. In fact, it is primarily Rasmus Nielsen who kept Kierkegaard’s ideas alive in the years immediately after Kierkegaard’s death (1855), and until Georg Brandes wrote a book about him in 1877.5 (In 1892, Høffding published a second book about Kierkegaard, focusing on his philosophical contributions. These two had been in Nielsen’s classes in the 1860s, when Kierkegaard appeared as a prominent figure.)
One big mystery about Rasmus Nielsen is why his interaction with Kierkegaard’s philosophy led him to undertake a study of the natural sciences and their methods. One might have expected the complete opposite, i.e. that becoming convinced of Kierkegaard’s point of view would push one further away from “science”. To the contrary, Nielsen decided that philosophers needed to study ‘naturvidenskaberne’, i.e. the natural sciences.
(Nielsen’s later works include detailed discussion of recent advances in mathematics, physics, chemistry, biology, and psychology. Nielsen introduced Darwin’s theory of evolution to Denmark, and he argued that it is perfectly compatible with traditional Christian doctrines.) Nielsen was, in an important sense, the first dedicated philosopher of science in European history.
Rasmus Nielsen was also one of the first philosophers to grapple with the consequences of Darwin’s theory of evolution.
Since Descartes, physicists have typically assumed that the only legitimate explanations of phenomena are mechanical. It’s quite surprising, then, that Bohr had a more positive view of explanations in terms of purposes and final causes.
In Aristotelian natural philosophy, it’s perfectly reasonable to give teleological explanations, i.e. in terms of final causes. The invocation of final causes was challenged by Galileo, Descartes, and other early modern scientists. They proposed, instead, to explain in terms of efficient causes, and more specifically, in terms of mechanisms.
There were, of course, several philosophers who weren’t convinced that mechanical explanation suffices. For example, Leibniz had his monads with entelechies, and Berkeley thought that change always traced back to an agent’s action.
In the Critique of Judgment, Kant argued that thinking in terms of final causes does play a positive role in scientific reasoning. As a result, the debate between mechanism and teleology was back on the table in the 19th century.
Many people associate Kierkegaard’s name with the phrase “leap of faith”, and they naturally assume that Kierkegaard advocated blind faith, both in God and in Christian doctrine. Even in university classrooms, Kierkegaard is frequently used as an example of a “fideist”, i.e. a person who holds that religious truth is beyond the reach of human reason.
The true story about Kierkegaard is, of course, much more complicated. To a zeroeth approximation, Kierkegaard was a critic of “Reason”. But Kierkegaard was in a context, and in that context, “Reason” was G.F.W. Hegel’s “Wissen” and “Wissenschaft”. If you know anything about Hegel, you know that his notion of “Wissen” is a far cry from the pedestrian notion of believing things on the basis of sufficient evidence. The point is that we need to be cautious about putting Kierkegaard in a box that simply doesn’t make sense for his context.
As mentioned before, Nielsen — unlike Kierkegaard — was inspired by the natural sciences. He believed that science (Videnskab) is an essential part of the task of human life, and that it delivers great goods to human kind.
Nielsen had been working up to it for many years, and in his book Grundideernes Logik (1864), he states it directly:
Faith and reason are different kinds of things.6
As we can see from his lecture notes, Nielsen had long been preaching this lesson to his students. However, the publication of the overt statement was the occasion for a backlash, and most notably by Georg Brandes who wrote the pamphlet Dualisme i vores nyeste Philosophie (1866). (Brandes, born in 1842, had just completed his degree at KU.) In this pamphlet, Brandes attacks Nielsen’s conception of the relation between faith and reason, arguing that it is as psychological impossibility to have a faith that is uninformed by considerations of a rational nature.
From 1869 to 1873, Rasmus Nielsen and collaborators published a journal called “For Ide og Virkelighed” (For Idea and Reality), coming to eight volumes in total. The intention seems to have been to resist the forces of secularism, and what came to be known as the Modern Breakthrough. Nielsen’s co-editors were Rudolf Schmidt and the Norwegian novelist Bjørnstjerne Bjørnson.
It is not clear how much medieval philosophy Rasmus Nielsen knew. Nonetheless, there are incredibly strong parallels between Rasmus Nielsen’s views on faith and reason and the medieval doctrine of two truths (Averroes, Boetius of Dacia, Siger of Brabant). The doctrine of two truths says essentially that a proposition might be true from the point of view of science but false from the point of view of faith.
It would be too much of a stretch to think that Rasmus Nielsen’s views on faith and reason had any direct influence on Niels Bohr — certainly not on the question of faith and reason, and not even on Bohr’s idea of “complementary” viewpoints. (Bohr is very tolerant about religion, and sees value in it, but he definitely rejects its claims upon him.) Nonetheless, it is perhaps culturally telling that both of these Danes thought of reality as “fragmented”, or more accurately, as requiring fragmented points of view.
There is much work still to be done in figuring out what Rasmus Nielsen’s views and arguments were — and teasing out the good ideas, if there are any. (It’s another task, of course, to try to tease out the ways in which Nielsen influenced subsequent Danish thinkers, and perhaps indirectly, other thinkers outside of Denmark.) Besides his many published works (all in Danish), Nielsen left handwritten notes that have been preserved by the Royal Library of Denmark. The library also maintains notes written by several of his students, including Høffding.
(Asmussen 1911) (Rosenberg 1903) (Koch 2016) (Høffding 1909) (Klein and Rosenberg 1909) (Stewart 2016)
Not a single one of the thousands of pages that Nielsen wrote has been translated into a “world language”. Moreover, none of Nielsen’s books has been re-printed in Danish.↩︎
There are some short expressions of admiration in the literature – after all, Nielsen had been their teacher. But there is only one place, to our knowledge, where there is explicit engagement with Nielsen’s philosophy: in Høffding’s book Danske Filosoffer. Here Høffding argues that Nielsen’s entire philosophy simply doesn’t work. Of course, Høffding reduces Nielsen’s philosophy to a single point (which, to be fair, was Nielsen’s main point): knowledge is possible only if God exists.↩︎
See, for example, https://www.google.dk/books/edition/Logik_og_Psychologie_Cursus_for_Universi/vnhZAAAAcAAJ?hl=en&gbpv=1↩︎
Høffding explicitly acknowledges his debt to Kierkegaard in his autobiography, Erindringer.↩︎
Høffding recalled: “Det var Rasmus Nielsen og Sibbern, der bleve mine første filosofiske Lærere. Rasmus Nielsen stod dengang paa sit Højdepunkt. Han var endnu søgende, betagen af Kierkegaard og optagen af matematiske og naturvidenskabelige Studier, stræbende at finde en Vej, ad hvilken disse forskellige Tankeverdener kunde forenes. Hans propædeutiske Forelæsninger bestode i mit Aar dels i en Gennemgang af Kierkegaards „Stadier“ , paa Grundlag af et lille Udvalg, han havde ladet trykke, dels i et kort erkendelsesteoretisk Omrids. Han talte med Liv og Kraft, ofte aandfuldt og vittigt, og jeg skylder disse Forelæsninger overordentligt meget. De satte en Mængde Tanker i Bevægelse hos mig, som hidtil ikke havde rørt sig.” (p 39)↩︎
“Tro og Viden er uensartede størrelser.”↩︎