The method used in the following chapters of the book is referred to in mathematics as an axiomatic approach. From the analysis of empirical data of the Kepler satellite hypotheses are drawn, which are called approaches and axioms. The derived statements are formulated as sentences to which certain probabilities are assigned. All axioms and sentences lead to an overall presentation of the situation, which can then be used as a working hypothesis. Namely as a working hypothesis regarding the abundance of habitable, Earth-like planets, as well as life, intelligence and civilizations in our galaxy. It is unprobable that we are alone in the universe. It is more probable that we are not alone.
