The concluding chapter (IX.) of the Book reflects on the great
difficulty of hitting the mean in all things, and of correctly
estimating all the requisite circumstances, in each particular case.
He gives as practical rules:--To avoid at all events the worst
extreme; to keep farthest from our natural bent; to guard against the
snare of pleasure. Slight mistakes on either side are little blamed,
but grave and conspicuous cases incur severe censure. Yet how far the
censure ought to go, is difficult to lay down beforehand in general
terms. There is the same difficulty in regard to all particular cases,
and all the facts of sense: which must be left, after all, to the
judgment of Sensible Perception [Greek: aisthaesis].
