of dealing with sin
may be illustrated by another analogy. The two processes depend upon two
different natural principles. The Mutilation of a member, for instance,
finds its analogue in the horticultural operation of _pruning_, where
the object is to divert life from a useless into a useful channel. A
part of a plant which previously monopolized a large share of the vigor
of the total organism, but without yielding any adequate return, is
suddenly cut off, so that the vital processes may proceed more actively
in some fruitful parts. Christ's use of this figure is well-known:
"Every branch in Me that beareth not fruit He purgeth it that it may
bring forth more fruit." The strength of the plant, that is, being given
to the formation of mere wood, a number of useless correspondences have
to be abruptly closed while the useful connections are allowed to
remain. The Mortification of a member, again, is based on the Law of
Degeneration. The useless member here is not cut off, but simply
relieved as much as possible of all exercise. This encourages the
gradual decay of the parts, and as it is more and more neglected it
ceases to be a channel for life at all. So an organism "mortifies" its
members.

Thirdly, Limitation. While a large number of correspondences between man
and his environment can be stopped in these ways, there are many more
which neither can be reduced by a gradual Mortification nor cut short by
sudden Death. One reason for this is that to tamper with these
correspondences might involve injury to closely related vital parts. Or,
again, there are organs which are really essential to the normal life of
the organism, and which therefore the organism cannot afford to lose
even though at times they act prejudicially. Not a few correspondences,
for instance, are not wrong in themselves but only in their extremes. Up
to a certain point they are lawful and necessary; beyond that point they
may become not only unnecessary but sinful. The appropriate treatment in
these and similar cases consists in a process of Limitation. The
performance of this operation, it must be confessed, requires a most
delicate hand. It is an art, moreover, which no one can teach another.
And yet, if it is not learned by all who are trying to lead the
Christian life, it cannot be for want of practice. For, as we shall see,
the Christian is called upon to exercise few things more frequently.

An easy illustration of a correspondence which is onl