Evidently it is a difficult and uncertain process; to be exact, or nearly so, requires rare powers of observation and, at each step, a great deal of tact, for a nice calculation has to be made on given quantities imperfectly ascertained and imperfectly noted![1115] Any political leader who does this successfully, does it through the ripest experience associated with genius.

And even then he keeps his hand on the check-rein in pushing his innovation or reform; he is almost always tentative; he applies his law only in part, gradually and provisionally; he wishes to ascertain its effect; he is always ready to stay its operation, amend it, or modify it, according to the good or ill results of experiment; the state of the human material he has to deal with is never clear to his mind, even when superior, until after many and repeated gropings .-- Now the Jacobin pursues just the opposite course.

His principle is an axiom of political geometry, which always carries its own proof along with it; for, like the axioms of common geometry, it is formed out of the combination of a few simple ideas, and its evidence imposes itself at once on all minds capable of embracing in one conception the two terms of which it is the aggregate expression.
Man in general, the rights of Man, the social contract, liberty, equality, reason, nature, the people, tyrants, are examples of these basic concepts: whether precise or not, they fill the brain of the new sectarian.

Often these terms are merely vague and grandiose words, but that makes no difference; as soon as they meet in his brain an axiom springs out of them that can be instantly and absolutely applied on every occasion and to excess.

Mankind as it is does not concern him.