On Literary Terms...and Reality

There are certain literary terms which I have been using freely and uncritically for the best part of forty to fifty years, concepts which seem to have no scientific basis, if we wish to talk in terms of 'objective reality'.

I am thinking of words, phrases and concepts like "the Absurd" (Camus), "Catharsis/Katharsis" (Aristotle), "Inscape and Instress" (Hopkins), and terms like "Metaphysical" as applied to Donne and others.

Yet I think I understand the meaning of these words. I've always recognised "the Absurd", I've occasionally experienced something akin to "katharsis" when watching a Greek tragedy, Shakespeare's "King Lear" or listening to a profound blues song, and Hopkins' concept of "inscape" makes absolute sense if one takes the trouble to look closely at natural phenomena, even something as simple as a frost-covered branch, a leaf, or a hollow old oak-stump.

A sketch by  Gerard Manley Hopkins: Hampstead. 1862. Oak-stump.

"And for all this, nature is never spent;

  There lives the dearest freshness deep down things"

(Hopkins)