individual member of society is to refrain from all acts, employments,
or recreations that may imperil life or health, and of society
collectively, to furnish a police-force adequate to the protection of its
members, to forbid and punish all crimes of violence, to enact and
maintain proper sanitary regulations, and to suppress such nuisances as
may be not only annoying, but harmful.

But the citizen is entitled to protection, only so long as he refrains
from acts by which he puts other lives in peril. If he assault another man
with a deadly weapon, and his own life be taken in the encounter, the
slayer has violated no right, nay, so far as moral considerations are
concerned, he is not even the slayer; for the man who wrongfully puts
himself in a position in which another life can be protected only at the
peril of his own, if his own be forfeited, has virtually committed
suicide. Nor is the case materially altered, if a man in performing an
unlawful act puts himself in a position in which he may be reasonably
supposed to intend violence. Thus, while both law and conscience would
condemn me if I killed a thief in broad daylight, in order to protect my
property,--if a burglar enter my house by night with no intention of
violence, and yet in the surprise and darkness of the hour I have reason
to suppose my life and the lives of my family in danger from him, the law
regards my slaying of such a person as justifiable homicide; and my
conscience would acquit me in defending the right to life appertaining to
my family and myself, against one whose intention or willingness to commit
violence was to be reasonably inferred from his own unlawful act.

Society, through the agency of law, in some cases and directions limits
the right of the individual citizen to life, and this *to the contingent
benefit of each,--to the absolute benefit of all*. So long as men are less
than perfect in character and condition, there must of necessity be some
sacrifice of life; but this sacrifice may be reduced to its _minimum_ by
judicious legislation. Now, if without such legislation the percentage of
deaths would be numerically much higher than under well-framed laws, the
lives sacrificed under these laws are simply cases in which the right of
the individual is made to yield to the paramount rights of the community.
Thus, there can be no doubt, that contagious disease of the most malignant
type could, in many cases, be more successfully treated at t