The language of deductive logic does a rather poor job of tracking the rhythms and patterns of natural language, but it can shed some light on linguistic behaviour. This post is a short introduction to the consequences of contradiction, discussed next.
Two arguing positions require an expenditure of energy: when we challenge the truth of our opponent’s statement and when we defend the truth of ours. How do we do this?
Facts, figures, examples, sometimes definitions work best. Eloquence helps. This is the high art of arguing. The low art – the circus or Punch-and-Judy type of argument – is different, and not entirely unfamiliar to logicians.
To challenge an opponent’s statement, we conjoin a ridiculously false statement of our own (the ridicule amplifies the effect) to our opponent’s statement. ‘And pigs might fly,’ is the English language handy option. The key word is ‘and’. Whether the opponent’s statement is true or false, ‘and’ will make the whole statement false. Conjunction is true only if both conjuncts are true.
How do we defend the truth of our statement? We add a new statement to the argument – by disjunction. This is a more subtle technique. Here is an illustration:
A: There is a deep state in America.
B: Really?
A: Yes. Either that or we are being manipulated by big corporations.
The key word is ‘or’. If we somehow manage to legitimize just one of these statements, the whole comes out true, because a disjunction is false only when both disjuncts are false.