The a` priori reasoners upon government are, of all plausible people, the most preposterous. They only argue too cleverly to permit my thinking them silly enough to be themselves deceived by their own arguments. Yet even this is posssible; for there is something in the vanity of logic which addles a man's brains. Your true logician gets, in time, to be logicalized, and then, so far as regards himself, the universe is one word. A thing, for him, no longer exists. He deposits upon a sheet of paper a certain assemblage of syllables, and fancies that their meaning is riveted by the act of deposition. I am serious in the opinion that some such process of thought passes through the mind of the "practised" logician, as he makes note of the thesis proposed. He is not aware that he thinks in this way--but, unwittingly, he so thinks. The syllables deposited acquire, in his view, a new character. While afloat in his brain, he might have been brought to admit the possibility that those syllables were variable exponents of various phases of thought; but he will not admit this if he once gets them upon the paper.
In a single page of "Mill," I find the word "force" employed four times; and each employment varies the idea. The fact is that a` priori argument is much worse than useless except in the mathematical sciences, where it is possible to obtain precise meanings. If there is any one subject in the world to which it is utterly and radically inapplicable, that subject is Government. The identical arguments used to sustain Mr. Bentham's positions, might, with little exercise of ingenuity, be made to overthrow them; and, by ringing small changes on the words "leg of mutton," and "turnip" (changes so gradual as to escape detection), I could "demonstrate" that a turnip was, is, and of right ought to be a leg of mutton.--Edgar Allan Poe