The reasonable and the unreasonable

In the present era, talk about the reasonable and the unreasonable has emerged. What is unreasonable has become a fad that is taking place everywhere, so that we can call this era the era of the absurd, whether in changing aspects of behavior and customs, or even in scientific matters in which inventions have become like amazing supernatural things.
What was unreasonable in the view of the ancients and until very recently has become something reasonable. What was considered reasonable has become unreasonable. This requires us to look into the matter of what is reasonable and what is unreasonable, and to determine what is actually meant by it. This will only be explained through this entire research.