Niels Bohr as a Physicist of Principle
Abstract
Our main claim is that Bohr adopted a principle-theoretic approach to quantum mechanics in order to reconcile two principles: the distinction principle, which asserts the necessity of a clear epistemic distinction between a classical apparatus and a quantum system, and the non-separability principle, which asserts that the two systems are ontologically non-separable in any measurement process. The latter principle is a consequence of Bohr's argument that, during a measurement interaction, the quantum system and the measurement apparatus form a 'new kind of individuality'. To support our argument, we first demonstrate the overlooked fact that, according to Bohr, the measurement interaction is a physical, irreversible process and not merely an epistemic acquisition of new information. In this respect, quantum mechanics must be regarded not only as a universal theory, but also as revealing no non-arbitrary difference between a quantum realm and a classical realm; the distinction is purely pragmatic. The tension between the epistemic necessity to rely on a neatly distinguishable classical realm and the ontic non-separability of the quantum system and the classical apparatus inclined Bohr to refuse to provide a constructive account of the measurement process, such as that later proposed, for instance, by spontaneous dynamical reduction models.
Related
- Niels Bohr in North America (1923) and his Meeting with Robert Frost
- Arithmetic of Bohr Frequencies Governs Uniform Mixing in Randomly Timed Quantum Spin Chains
- Classical Electromagnetic Derivation of the Bohr Spectrum
- Radial power-like potentials: from the Bohr-Sommerfeld ℓ ≠ 0 state energies to the exact ones
- Entangled Merged Pairs: The Observation-Boundary Principle
BibTeX
@misc{dorato2026niels,
title = {{Niels Bohr as a Physicist of Principle}},
author = {Mauro Dorato and Jan Faye},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.04297},
eprint = {2609.04297},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.04297},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Niels Bohr as a Physicist of Principle
AU - Mauro Dorato
AU - Jan Faye
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2609.04297
UR - https://arxiv.org/abs/2609.04297
AB - Our main claim is that Bohr adopted a principle-theoretic approach to quantum mechanics in order to reconcile two principles: the distinction principle, which asserts the necessity of a clear epistemic distinction between a classical apparatus and a quantum system, and the non-separability principle, which asserts that the two systems are ontologically non-separable in any measurement process. The latter principle is a consequence of Bohr's argument that, during a measurement interaction, the quantum system and the measurement apparatus form a 'new kind of individuality'. To support our argument, we first demonstrate the overlooked fact that, according to Bohr, the measurement interaction is a physical, irreversible process and not merely an epistemic acquisition of new information. In this respect, quantum mechanics must be regarded not only as a universal theory, but also as revealing no non-arbitrary difference between a quantum realm and a classical realm; the distinction is purely pragmatic. The tension between the epistemic necessity to rely on a neatly distinguishable classical realm and the ontic non-separability of the quantum system and the classical apparatus inclined Bohr to refuse to provide a constructive account of the measurement process, such as that later proposed, for instance, by spontaneous dynamical reduction models.
ER -