Quantum Logic versus Alternative Approaches

Abstract

In the present paper we will discuss the following problem: Is the external reality primarily a quantum world such that in macroscopic dimensions classical properties evolve by decoherence and emergency? -- Or is there only a classical, macroscopic world of apparatuses and observers, and what we can say about the quantum world is nothing but a consistent way of speaking which illustrates without any ontological commitments merely the formalism of quantum mechanics?