On the one hand poetry is useless. It can't change the world materially. On the other hand it is a basic part of human existence. It came into the world when humans did. It's what makes human beings human.
Yes, yes, I see it all! — an enormous social activity, a mighty civilization, a profuseness of science, of art, of industry, of morality, and afterwords, when we have filled the world with industrial marvels, with great factories, with roads, museums and libraries, we shall fall exhausted at the foot of it all, and it will subsist — for whom? Was man made for science or was science made for man?