1: Open Problems of the Present-Day Theoretical Chemistry.- 1.1 The Overproduction of Truth.- 1.2 Chemical Theories.- 1.3 "We can calculate everything".- 1.4 Some Puzzles of Molecular Quantum Mechanics.- 1.5 New Points of View Are Needed.- 2: On the Structure of Scientific Theories.- 2.1 A Good Theory should be Consistent, Confirmed and Intuitable.- 2.2 No Theory can be Proved to be Free from Inner Contradictions.- 2.3 Experiments can neither Prove a Theory True nor False.- 2.4 Preconceptions and Prior Conceptions.- 2.5 There is no Insight without Inner Pictures.- 2.6 Are Theories dangerous?.- 2.7 Summing Up.- 3: Pioneer Quantum Mechanics and its Interpretation.- 3.1 Introductory Remarks and Preview.- 3.2 The Historical Development of the Hilbert-Space Model of Pioneer Quantum Mechanics.- 3.3# Outline of the Hilbert-Space Formalism of Pioneer Quantum Mechanics.- 3.4 The Copenhagen Interpretation of Pioneer Quantum Mechanics.- 3.5 The von Neumann-London-Bauer Interpretation of Pioneer Quantum Mechanics.- 3.6 The Everett Interpretation of Pioneer Quantum Mechanics.- 3.7 Einstein-Podolsky-Rosen Correlations.- 3.8 Conclusion: The Status of Pioneer Quantum Mechanics.- 4: Beyond Pioneer Quantum Mechanics.- 4.1 Introduction.- 4.2 Algebraic Quantum Mechanics.- 4.3# Algebraic Statistical Mechanics.- 4.4 The Development of Quantum Logics.- 4.5# Non-Boolean Probability Theory.- 4.6 Interrelations and Synthesis.- 5: A Framework for Theoretical Chemistry.- 5.1 Reevaluation for the Paradigms of Theoretical Chemistry.- 5.2 The Logic of Properties.- 5.3 Orthomodular Temporal Logic and its Ontic Interpretation.- 5.4 W*-Logic for Chemistry.- 5.5 Theory Reduction.- 5.6 Objects in a Quantum World.- 6: Reductionism, Holism and Complementarity.- 6.1 The Controversy Reductionism vs.Holism.- 6.2 Complex Systems.- 6.3 Patterns in Holistic Systems.- 6.4 A New Look at Molecular Patterns.- 6.5 One Way of Telling is not Enough.- Bibliography and Author Index.