Practical Principle of Contradiction

Because an Utterance that sends 'mixed signals', i. e. entails 'Do X and do not do X', is impossible to enact, it is self-defeating qua Communication.  Accordingly, internal coherence is a necessary condition of successful Communication, or, in other words, Communication is governed by a Practical Principle of Contradiction, which, as has been previously discussed, is arguably independent of its more familiar Theoretical counterpart.  Now, the scope of the Principle can be extended beyond a single Utterance, by a single speaker, to all Utterances, by that or all speakers.  So, inconsistencies over time erode not only all the attempts to Communicate by that speaker, but Communication in general.