Actually, "something I re-read while typing notes and excerpts into the computer from something I read not to long ago." But that's a minor detail.
This from Biographia Literaria, from the second of "Satyrane's Letters," which are situated in between chapters 22 and 23 (pages 186-87 in the Engell and Bate Collected Works edition).
Hold! (methinks I hear the spokesman of the crowd reply, and we will listen to him. I am the plaintiff, and he is the defendant.)
DEFENDANT: Hold! are not our modern sentimental plays filled with the best Christian morality?
PLAINTIFF: Yes! just as much of it, and just that part of it which you can exercise without a single Christian virtue – without a single sacrifice that is really painful to you! – just as much as flatters you, sends you away pleased with your own hearts, and quite reconciled to your vices, which can never be thought very ill of, when they keep such good company, and walk hand in hand with so much compassion and generosity; adulation so loathsome, that you would spit in the man’s face who dared offer it to you in a private company, unless you interpreted it as insulting irony, you appropriate with infinite satisfaction, when you share the garbage with the whole stye, and gobble it out of a common trough. No  Caesar must pace your boards – no Antony, no royal Dane, no Orestes, no Andromache! –
D. No: or as few of them as possible. What plain citizen of London, or Hamburg, to do with your kings and queens, and your old school-boy Pagan heroes? Besides, every body knows the stories: and what curiosity can we feel ------
P. What, Sir, not for the manner? not for the delightful language of the poet? not for the situations, the action and reaction of the passions?
D. You are hasty, Sir! the only curiosity, we feel, is in the story: and how can we be anxious concerning the end of a play, or be surprized by it, when we know how it will turn out?
P. Your pardon, for having interrupted you! we no understand each other. You seek then, in a tragedy, which wise men of old held for the highest effort of human genius, the same gratification, as that you receive from a new novel, the last German romance, and other dainties of the day, which can be enjoyed but once. If you carry these feelings to the sister art of Painting, Michael Angelo’s Sistene Chapel, and the Scripture Gallery of Raphael, can expect no favour from you. You know all about them beforehand; and are, doubtless, more familiar with the subjects of those paintings, than with the tragic tales of the historic or heroic ages. There is consistency, therefore, in your preference of contemporary writers: for the great men of former times, those at least who were deemed great by our ancestors, sought so little to gratify this kind of curiosity, that they seemed to have regarded the story in a not much higher light, than the painter regards his canvass: as that on not by, which they were to display their appropriate excellence.