one more bit of the postscript (the translations here are by swenson and lowrie, now superseded by the hongs' translation, which is at any rate not as felicitous as english prose):

In a merely subjective determination of the truth, madness and truth become in the last analysis indistinguishable, since they may both have inwardness. Nevertheless, perhaps I may here venture to offer a little remark, one which would seem to be not wholly superfluous in an objective age. The absence of inwardness is also madness. The objective truth as such is by no means adequate to determine that whoever utters it is sane; on the contrary, it may even betray the fact that he is mad, although what he says may be entirely true, and especially objectively true.

I shall here permit myself to tell a story, which without any sort of adaptation on my part comes direct from an asylum. A patient in such an institution seeks to escape, and actually succeeds in effecting his purpose by leaping out of a window, and prepares to start on the road to freedom, when the thought strikes him (shall I say sanely enough or madly enough?): "When you come to town you will be recognized, and you will at once be brought back here again; hence you need to prepare yourself fully to convince everyone by the objective truth of what you say, that all is in order as far as your sanity is concerned." As he walks along and thinks about this, he sees a ball lying on the ground, picks it up, and puts it into the tail pocket of his coat. Every step he takes the ball strikes him, politely speaking, on his hinder parts, and every time it thus strikes him he says: "Bang, the earth is round." He comes to the city, and at once calls on one of his friends; he wants to convince him that he is not crazy, and therefore walks back and forth, saying continually: "Bang, the earth is round!"

But is not the earth round? Does the asylum still crave yet another sacrifice for this opinion, as in the time when all men believed it to be flat as a pancake? Or is a man who hopes to prove that he is sane, by uttering a generally accepted and generally respected objective truth, insane? And yet it was clear to the physician that the patient was not yet cured; though it is not to be thought that the cure would consist in getting him to accept the opinion that the earth is flat. 

there's plenty to be said for kant, hegel, schelling, fichte, etc. however, putting the thing gently, they just didn't write this well. if he has a predecessor as a writer and a thinker, it's schiller. but schiller is not anywhere near the thinker that sk is.