Refusal to believe until proof is given is a rational position; denial of all outside of our own limited experience is absurd.
A monomaniac is a sick person whose mentality is perfectly healthy in all respects but one; he has a single flaw, clearly localized. At times, for example, he has an unreasonable and absurd desire to drink or steal or use abusive language; but all his other acts and all his other thoughts are strictly correct.
The history of thought may be summed up in these words: it is absurd by what it seeks and great by what it finds.
My turn of mind is so given to taking things in the absurd point of view, that it breaks out in spite of me every now and then.
Only she who attempts the absurd can achieve the impossible.
Whatsoever is contrary to nature is contrary to reason, and whatsoever is contrary to reason is absurd.