By far, the most influential philosopher to come out of Copenhagen was Søren Kierkegaard 1813-1855. For a child growing up in Copenhagen in the late 1800s, Kierkegaard’s ideas were simply part of the common cultural inheritance. This would have been especially true for Niels Bohr, growing up in an intellectual home, and one that received frequent visits from the author of the first book about Kierkegaard’s philosophy.
The historian of physics Max Jammer claimed that Kierkegaard’s ideas influenced Bohr (Jammer 1966).
Jammer’s claim was vociferously rejected by Leon Rosenfeld (Rosenfeld 1969).
Rosenfeld’s stance on Kierkegaard also seems to have rubbed off on David Favrholdt, who put a lot of effort into explaining why there couldn’t possibly have been any positive influence of Kierkegaard on Bohr.
(Rosfort 2013) (Halvorson 2023)
One might think that Kierkegaard isn’t interested in metaphysics or logic – as analytic philosophers understand these terms. But that would be a mistake. In fact, Kierkegaard believes that bad views about these subjects lead to confused views about one’s self and one’s task in life.
“I don’t have a system, but I do have a worldview”
Den første betragtingsmåde ser mennesket udefra, som objekt, – den anden betragtningsmåde ser mennesket indefra, oplever det som subjekt. Det ‘hele’ menneske kan ikke gøres til genstand for udvendig betragtning, det kan kun opleves indefra. (Villy Sørensen, Introduction to The Concept of Anxiety)
We have direct evidence that Bohr read Kierkegaard’s Stages on Life’s Way – which is not one of Kierkegaard’s more explicitly epistemological works. It would be much more intriguing if we knew that Bohr had read Concluding Unscientific Postscript. Nonetheless, Høffding had read and absorbed all of these works, and had been shaped by Rasmus Nielsen, whose entire epistemology was Kierkegaard-inspired.