We’ve been talking about the law of non-contradiction (LNC), which says that the statements p and not-p cannot both be true. (In symbolic notation: ~ (p • ~p) ) We briefly noted Aristotle’s view that skepticism about LNC cannot be made a coherent position. Let’s now consider a famous remark on the subject by the Islamic philosopher Avicenna or Ibn Sina (c. 970-1037). In The Metaphysics of the Healing, he says of such a skeptic:
As for the obstinate, he must be plunged into fire, since fire and non-fire are identical. Let him be beaten, since suffering and not suffering are the same. Let him be deprived of food and drink, since eating and drinking are identical to abstaining. (Quoted in the SEP article “Contradiction”)