It is not worth our while to discuss, like sophisters, whether, in
no case, some evil, for the sake of some benefit, is to be tolerated.
Nothing universal can be rationally affirmed on any moral or any
political subject. Pure metaphysical abstraction does not belong
to these matters. The lines of morality are not like ideal lines of
mathematics. They are broad and deep as well as long. They admit
of exceptions; they demand modifications. These exceptions and
modifications are not made by the process of logic, but by the rules
of prudence. Prudence is not only the first in rank of the virtues
political and moral, but she is the director, the regulator, the
standard of them all. Metaphysics cannot live without definition; but
prudence is cautious how she defines. Our courts cannot be more fearful
in suffering fictitious cases to be brought before them for eliciting
their determination on a point of law, than prudent moralists are in
putting extreme and hazardous cases of conscience upon emergencies not
existing. Without attempting therefore to define, what never can be
defined, the case of a revolution in government, this, I think, may be
safely affirmed, that a sore and pressing evil is to be removed, and
that a good, great in its amount, and unequivocal in its nature, must
be probable almost to certainty, before the inestimable price of our own
morals, and the well-being of a number of our fellow-citizens, is paid
for a revolution. If ever we ought to be economists even to parsimony,
it is in the voluntary production of evil. Every revolution contains in
it something of evil.