§ 1. I am afraid this will be a difficult chapter; one of drawbacks, qualifications, and exceptions. But the more I see of useful truths, the more I find that, like human beings, they are eminently biped; and, although, as far as apprehended by human intelligence, they are usually seen in a crane-like posture, standing on one leg, whenever they are to be stated so as to maintain themselves against all attack it is quite necessary they should stand on two, and have their complete balance on opposite fulcra.

§ 2. I doubt not that one objection with which, as well as with another, we may begin, has struck the reader very forcibly, after comparing the illustrations above given from Turner, Constable, and Claude. He will wonder how it was that Turner, finishing in this exquisite way, and giving truths by the thousand, where other painters gave only one or two, yet, of all painters, seemed to obtain least acknowledgeable resemblance to nature, so that the world cried out upon him for a madman, at the moment when he was giving exactly the highest and most consummate truth that had ever been seen in landscape.

And he will wonder why still there seems reason for this outcry. Still, after what analysis and proof of his being right have as yet been given, the reader may perhaps be saying to himself: “All this reasoning is of no use to me.[…]”