In the first part of this thesis, I examine how Bohr’s complementarity informs some dichotomies that have traditionally characterized the nature of knowing and being, namely those Cartesian or quasi-Cartesian divides of object/subject, human/non-human, knower/known and microscopic/macroscopic. In recent years, a few science studies scholars have argued that ‘complementary epistemology’ supports the postmodern turn connecting science and society. Prof Karen Barad (2007) has put forth her Agential Realism (AR hereafter), and Prof Arkady Plotnitsky (1994, 2006) has traced Bohr’s complementarity principle back to Bataille’s general economy (1988) and Derrida’s deconstructive economy (1967). In the second part of this thesis, I critically examine Barad’s and Plotnitsky’s interpretations of Bohr’s ideas to assess the extent to which quantum mechanics may legitimately inform their views. In the third part of this thesis, I focus on Bohr’s complementarity as a standalone theoretical framework. Bohr famously spoke of complementarity in fields such as biology, psychology, or anthropology (Bala 2017); however, this is not the sense in which the concept of complementarity was used in physics, where it describes the particle/wave dual nature of matter. In the aforementioned fields, complementarity, I argue, signals a relationship of mutual exclusivity yet equal necessity between concepts or modes of description. Against Barad and Plotnitsky, I argue that this ‘conceptual’ sense of complementarity does not reduce to a question of applicability of complementarity beyond physics; first, talk of application is historically inadequate and, second, Bohr seems to be embarked on a larger project, where complementarity describes an epistemological attitude in our inquiring about men and the world.