Adler sees no point in discussing anything with the extreme skeptic and I agree.
****What is the answer to the skeptic who claims that the effort to get at the truth is always in vain? …
The person who maintains that he knows nothing because nothing is knowable, or who declares that no statement can be either true or false, interdicts himself from telling lies. His extreme skepticism removes him from the ordinary world in which most of us live and in which, according to him, we live under the illusion that we can discriminate between statements that are true and statements that are false. …
The definition of truth involves an erroneous presupposition, the skeptic charges. Does not his use of the word “erroneously” trip him up? Has he not contradicted himself by saying, on the one hand, that nothing is either true or false and yet saying, on the other hand, that the presupposition involved in the definition of truth is an erroneous presupposition or, in other words, false?
We are verging here on an age-old reply to the extreme skeptic that dismisses him as refuting himself. One cannot say that no statements are true or false, or that there is no such thing as truth in the sense defined, without contradicting oneself. If the statement that expresses the skeptic’s view about truth is one that he himself regards as true, then at least one statement is true. If it is false, then it is quite possible for many other statements to be either true or false. If the statement that expresses the skeptic’s view is neither true nor false, then why should we pay any attention to what he says?
Either he has contradicted himself or he has impelled us to discontinue any further conversation with him on the grounds that it can lead nowhere. There is no point in talking to someone who is willing to answer any question by saying both yes and no at the same time. Since the extreme skeptic does not acknowledge the restraint imposed by the rule of reason that we ought not to contradict ourselves if we can avoid doing so, our refutation of him by appealing to that rule does not silence him. He has no objection to being unreasonable. We may have refuted him to our own satisfaction, but that does not carry with it an acknowledgment by him that he has been refuted and should abandon his skepticism. The only consequence that follows from our regarding his view as self-contradictory and therefore self-refuting is the judgment we may be forced to make that there is no point in carrying on the conversation with him any further.
The commonsense view is the one that all of us embrace when we reject the self-contradictory and self-refuting position of the extreme skeptic as being not only unreasonable, but also impracticable. ****