In enhancing the validity of living theories I recommend the use of Habermas, J. (1976) Communication and the evolution of society. London : Heinemann

“I shall develop the thesis that anyone acting communicatively must, in performing any speech action, raise universal validity claims and suppose that they can be vindicated (or redeemed: eislösen). Insofar as he wants to participate in a process of reaching understanding, he cannot avoid raising the following – and indeed precisely the following – validity claims. He claims to be:

a. Uttering something understandably;

b. Giving (the hearer) something to understand;

c. Making himself thereby understandable; and

d. Coming to an understanding with another person.

The speaker must choose a comprehensible expression (verständlich) so that speaker and hearer can understand one another. The speaker must have the intention of communicating a true (wahr)proposition (or a propositional content, the existential presuppositions of which are satisfied) so that the hearer can share the knowledge of the speaker. The speaker must want to express his intentions truthfully (wahrhaftig) so that the hearer can believe the utterance of the speaker (can trust him). Finally, the speaker must choose an utterance that is right (richtig) so that the hearer can accept the utterance and speaker and hearer can agree with one another in the utterance with respect to a recognized normative background. Moreover, communicative action can continue undisturbed only as long as participants suppose that the validity claims they reciprocally raise are justified.” (Habermas, 1976, pp. 2-3)