[Truth and reality].

Communication presumes the truth of statements. According to H. Weyl, the direct occurrence is subjective and absolute, the objective world relative, represented by figures and symbols, after induction of a co-ordinate system into the world. Sentences shall express relations between persons, things and properties. The message of a sentence is true, if the facts of a case prove right in reality. Thomas von Aquin: "Veritas est adaequatio rei et intellectus." To recognize a fact the reception of both "objective" signs and "subjective" forming of models are necessary. The objective and the subjective are linked strongly in the cognition. A true sentence develops if the meaning of the signs, which derive from the facts are in harmony with those, which come from the sentence by itself. Signs have to be decoded (subjectively). The attempt of making accessible the "objective" world is done with a system of rules and methods, which is without contradiction and clear in itself. Reality can be recognized only in that manner in which language can present it. "A sentence is true, if the facts of the case, which is referred by the sentence, are true." The problem, the reference of this message by itself, was solved by Tarski, inducing the term "object language" and declaring the sentences as objects of the natural (meta-)language. There are no terms as "true" or "wrong" in the object language. K. R. Popper differentiates 3 worlds: world of reality, of subjectivity, and of objectivity. Communication results from the subjective world, she rouses up emotions and reflexes. Nevertheless objectivity remains the controlling instance for messages and imaginations of the subjective ideas. The objective ideas differ from subject ones because of the possibility of associating ideas of a certain class of constellation of signals to the reality (concrete ideas), or because they can be found in a system of rules, which enables one to associate to a constellation of signals and to control this association (abstract ideas). These ideas of the "3rd world" may be regarded as supervising instances for intersubjective communication.