“Crucially, in a stunning reversal of his forefather’s schema, Bohr rejects the atomistic metaphysics that takes “things” as ontologically basic entities. For Bohr, things do not have inherently determinate boundaries or properties, and words do not have inherently determinate meanings. Bohr also calls into question the related Cartesian belief in the inherent distinction between subject and object, and knower and known.” (Barad, “Posthumanist Performativity”, 813)

“Bohr’s break with Newton, Descartes, and Democritus is not based in “mere idle philosophical reflection” but on new empirical findings in the domain of atomic physics that came to light during the first quarter of the twentieth century. Bohr’s struggle to provide a theoretical understanding of these findings resulted in his radical proposal that an entirely new epistemological framework is required.” (814)

“In contrast to these Newtonian assumptions, Bohr argued that theoretical concepts are defined by the circumstances required for their measurement. It follows from this fact, and the fact that there is an empirically verifiable discontinuity in measurement interactions, that there is no unambiguous way to differentiate between the “object” and the “agencies of observation.” As no inherent cut exists between “object” and “agencies of observation,” measured values cannot be attributed to observation-independent objects. In fact, Bohr concluded that observation-independent objects do not possess well-defined inherent properties.” (Barad, “Getting Real”, 95)

Barad has a Ph.D. in theoretical physics. I do not. With that in mind, I read the sections of her articles on Bohr’s epistemology.

The first thing that I was reminded of was something my professor in philosophy of science mentioned years ago. She had been talking about quantum mechanics and indeterminacy, and said something briefly about Bohmian mechanics and hidden-variables. From what I remember, Bohmian mechanics is an interpretation of quantum mechanics which uses hidden or unobservable entities (pilot waves) to give classical, deterministic explanations of quantum phenomena. Quantum mechanics comes up in philosophical discussions to argue, as Barad does, against realism, and Bohmian mechanics are sometimes used in response. It is supposed to be mathematically equivalent to non-relativistic quantum mechanics. Although it seems today that Bohmian mechanics doesn’t provide a way back to purely classical formulations and it wouldn’t necessarily undermine Barad’s argument if it did, in Bohr’s time it wasn’t clear that the statistical interpretation was the only viable one (De Broglie offered the first ‘pilot wave’ explanation for quantum phenomena, and was contemporary with Bohr). I think it’s interesting that the point where she uses science to legitimate her philosophical claim is also the one place where she takes empirical fact to be transparent, and separates the ‘object’ (even if it is a ‘negative’ or ‘absent’ object, a boundary) from the ‘agencies of observation’ (Bohr). This is not to say that she depends only on Bohr’s philosophical arguments, or that I disagree with her general argument. But when I read through the articles for the first time, it all seemed to fit together very well. The thought in my head during my first reading was, ‘She cites a scientist. She is a scientist.’