The paper tries to offer an overall pragmatic perspective on the concepts 'knowledge', 'truth', and 'reality'. The perspective should also pick out the so-called metaphysics of 'true world' and show that the metaphysics is created by a long historical, and that's why unnecessary, tradition. This arbitrary tradition is a reason for popularity of the correspondence theory of truth, in spite of the fact that nobody can explain what 'correspondence' means exactly. The author contrasts this metaphysics with the pragmatic metaphysics of 'un-demarcation of organism and environment'. In the pragmatic terms, one truth is defined as a function of language, and hence as a function of the life.