of material resources, housing conditions, social environment as well as the person's physical condition. The lifeworld, in contrast, describes the subjective perception of these conditions. Kraus uses the epistemological distinction between subjective reality and objective reality. Thus, a person's lifeworld correlates with the person's life conditions in the same way that subjective reality correlates with objective reality. One is the insurmountable, subjective construct built depending on the other one's conditions. Kraus defined lifeworld and life conditions as follows:Life conditions mean a person's material and immaterial circumstances of life. Lifeworld means a person's subjective construction of reality, which he or she forms under the condition of his or her life circumstances. This contrasting comparison provides a conceptual specification, enabling in the first step the distinction between a subjectively experienced world and its material and social conditions and allowing in the second step to focus on these conditions' relevance for the subjective construction of reality. With this in mind, Manfred Ferdinand, who is reviewing the lifeworld terms used by Alfred Schütz, Edmund Husserl, Björn Kraus and Ludwig Wittgenstein, concludes: "Kraus' thoughts on a constructivist comprehension of lifeworlds contours the integration of micro-, meso- and macroscopic approaches, as it is demanded by Invernizzi and Butterwege: This integration is not only necessary in order to relate the subjective perspectives and the objective frame conditions to each other but also because the objective frame conditions obtain their relevance for the subjective lifeworlds not before they are perceived and assessed." A relational constructivist theory of power: Instructive vs. destructive power Björn Kraus deals with the epistemological perspective upon power regarding the question about possibilities of interpersonal influence by developing a special form of constructivism ("Machtanalytischer Konstruktivismus"). Instead of focussing on the valuation and distribution of power, he asks what the term can describe at all. Coming from Max Weber's definition of power, he realizes the term of power has to be split into "instructive power" and "destructive power". More precisely, instructive power means the chance to determine the actions and thoughts of another person, whereas destructive power means the chance to diminish the opportunities of another person. Kraus defined "instructive power" and "destructive power" as follows:"Instructive power" means the chance to determine a human's thinking or behaviour. (Instructive power as chance for instructive interaction is dependent on the instructed person's own will, which ultimately can refuse instructive power.) "Destructive power" means the chance to restrict a