Fuzzy logic is a well-established formalism in computer science being strongly influenced by the work of Zadeh [17, 16]. It provides us with a means to deal with vagueness and uncertainty. Fuzzy logic is based on t-norms and t-conorms for intersection and union, respectively, on membership values of fuzzy sets.Quantum logic was developed in the context of quantum mechanics. In contrast to fuzzy logic, the logic is not based on membership values but on vector subspaces identified by projectors. The lattice of all projectors provides us with a lattice operations interpreted as conjunction and disjunction.