out of hand or escape and do
damage, will restrain them or keep them within proper bounds? Just as
we may not go effectively about our several businesses in a society
dependent on a minute division of labor if we must constantly be on
guard against the aggressions or the want of forethought of our
neighbor, so our complex social order based on division of labor may
not function effectively if each of us must stay his activities
through fear of the breaking loose or getting out of hand of something
which his neighbor harbors or maintains. There is danger to the
general security not only in what men do and the way in which they do
it, but also in what they fail to do in not restraining things they
maintain or agencies they employ which may do injury if not kept
strictly in hand. The general security is threatened by wilful
aggression, by affirmative action without due regard for others in the
mode of conducting it, and by harboring and maintaining things and
employing agencies likely to escape or to go out of bounds and do
damage. Looked at in this way, the ultimate basis of delictal
liability is the social interest in the general security. This
interest is threatened or infringed in three ways: (1) Intentional
aggression, (2) negligent action, (3) failure to restrain potentially
dangerous things which one maintains or potentially dangerous agencies
which one employs. Accordingly these three are the immediate bases of
delictal liability.

Controversial cases of liability without fault involve the third
postulate. Systematic writers have found no difficulty in reconciling
the law of negligence with the will theory of liability and the
doctrine of no liability without fault. Yet they must use the term
fault in a strained sense in order to fit our law of negligence with
its objective standard of due care, or the Roman cases of liability
for _culpa_ judged by the abstract standard, into any theory of moral
blameworthiness. The doctrine of liability for fault and for fault
only has its roots in the stage of equity and natural law, when the
moral and the legal are identified, and means that one shall respond
for injuries due to morally blameworthy conduct upon his part. As Ames
puts it, "the unmoral standard of acting at one's peril" is replaced
by the question, "Was the act blameworthy?" But is an act blameworthy
because the actor has a slow reaction time or was born impulsive or is
naturally timid or is easily "rattled" and