This book is concerned with the development of the understanding of the relational structures of information, knowledge, decision–choice processes of problems and solutions in the theory and practice regarding diversity and unity principles of knowing, science, non-science, and information–knowledge systems through dualistic-polar conditions of variety existence and nonexistence. It is a continuation of the sequence of my epistemic works on the theories on fuzzy rationality, info-statics, info-dynamics, entropy, and their relational connectivity to information, language, knowing,...