Famously, Epictetus had an exchange with someone on the necessity, credibility and utility of logic:
How is logic necessary?
When someone in [Epictetus’] audience said, Convince me that logic is necessary, he answered: Do you wish me to demonstrate this to you?—Yes.—Well, then, must I use a demonstrative argument?—And when the questioner had agreed to that, Epictetus asked him. How, then, will you know if I impose upon you?—As the man had no answer to give, Epictetus said: Do you see how you yourself admit that all this instruction is necessary, if, without it, you cannot so much as know whether it is necessary or not? [Cf J. C. Wright]
However, many today miss the point. J C Wright picks up:
The difficulty the postmodernists have with the discussions of the role of reason, is that they accept the categorical fallacy that no categories exists aside from science (which is objective) and faith or opinion (which is arbitrary).
They reason in this fashion: Science, either empirical or rational, assumes a verification principle. Whatever is not open to verification is not science; and whatever is not science is arbitrary. Ergo whatever is not open to verification is arbitrary. Again, the laws of logic (such as modus ponens) are not open to verification; ergo, by modus ponens, they are arbitrary.
Of course, science depends for its own credibility on the first principles and duties of reason but as we see many, today, are inoculated against seeing that. JCW continues:
The problem is that another category of thought does exist: wisdom. A thing can be wise without being scientific. There is reasoning that exists larger than and including scientific reasoning: this is called natural reason or common sense. Scientific reasoning includes empiricism and axiomatic logic.
Empiricism has won such high regard that modern intellectuals dismiss axiomatic logic as unscientific (in other words, they take the axiom that axiomatic logic is not empirical; they take whatever is nonempirical to be mere opinion; and they conclude by Barbara [a syllogistic structure] that ergo axiomatic logic is mere opinion. The irony that they themselves use axiomatic logic to reach this conclusion, is, of course, lost on them).
With logic gone, natural reason is dismissed from academic discussion, and, with it, serious ethical reasoning. Common sense is banished from the discussion, and, with it, common sense. Wisdom is banished from the discussion, and, when it flies, all that is left is nonsense, either angry (Nietzsche) or despairing (Sartre).
Hence, of course, much that has gone wrong today.
And, it explains why when it is pointed out, correctly, that certain inescapable first principles and duties of reason are just that, inescapably, so self-evidently true and antecedent to proof, certain objectors wish to reject. Often, with the dismissive remark, one has not “proved” the matter.
But that’s the problem.
These are antecedent to proof and any attempt to prove pivots on them.
These, are where rationality starts.
To dismiss them, therefore, is to default to the irrational.
As, we are unfortunately seeing. Sad, but a sign of our en-darkened times. END