Chapter 12: Complementarity Transformed: Constructing Freedom on the Border

Different objects of investigation require different ways of making sense. Niels Bohr’s solution—the Complementarity Principle (CP)—was both sufficient and heuristically productive in the physics of the 20th century. It showed the sciences a way to overcome the confines of the classical logic—moving from the rejection of the truthfulness of negation (if A is, then non-A cannot be true) to that of complementarity of opposites (A can be true under conditions X, and non-A under conditions Y, with both views being complementary to each other). It is important to locate Bohr’s efforts in their historical context—still dominated by acceptance of the Aristotelian/Boolean classical logic, with new versions of logics—multivalued, deontic, temporal (Valsiner, 2009)—not yet being developed. One could consider Bohr’s solution a major revolution in logic carried out in one science—physics—under the conditions of the ways of knowledge construction in that discipline.