Poetry is sane because it floats easily in an infinite sea; reason seeks to cross the infinite sea and so make it finite. The result is mental exhaustion. To accept everything is an exercise, to understand everything a strain.
Nobody could catch cold by the sea; nobody wanted appetite by the sea; nobody wanted spirits; nobody wanted strength. Sea air was healing, softening, relaxing - fortifying and bracing - seemingly just as was wanted - sometimes one, sometimes the other. If the sea breeze failed, the seabath was the certain corrective; and where bathing disagreed, the sea air alone was evidently designed by nature for the cure.
You are now In London, that great sea, whose ebb and flow At once is deaf and loud, and on the shore Vomits its wrecks, and still howls on for more. Yet in its depth what treasures!