entering restricted areas are all examples of trespass. Note that trespass is often
a crime as well as a tort. Intentional wrongdoing is frequently criminal.
Trespass concerns the crossing of an owner’s boundaries. Today, trespass
usually refers to violating the physical boundaries of an owner’s land, but
in legal history trespass was the legal remedy for direct injuries caused by
another to one’s person as well. The famous British constitutional historian
Frederick Maitland wrote, “Trespass is the fertile mother of actions.” By this
he meant that many of our modern day causes of action in tort—like battery—
come from trespass. Now do you appreciate better the connection of tort
law to property in our legal system? In an important sense, we own ourselves
and various things we have acquired, and those who violate our boundaries
become liable to compensate us.
Conversion is the wrongful exercise of dominion (power) and control over
the personal (nonland) resources that belong to another. Conversion deprives
owners of their lawful right to exclude others from such resources. The deprivation
may be either temporary or permanent, but it must constitute a serious
invasion of the owner’s legal right. Abraham Lincoln once convinced
an Illinois court that a defendant’s action in riding the plaintiff’s horse for
15 miles was not sufficiently serious to be a conversion since the defendant
had returned the horse in good condition. The plaintiff had left the horse with
the defendant to be stabled and fed.
Conversion often arises in business situations. Stealing something from
an employer is conversion, as is purchasing—even innocently—something
that has been stolen. Failing to return something properly acquired at the
designated time, delivering something to the wrong party, and destruction or
alteration of what belongs to another are all conversions when a deprivation
of ownership is serious or long-lived. Even if you intend to return something,
if you have converted it you are absolutely liable for any damage done to it.
A warehouse operator who improperly transfers stored goods from a designated
to a nondesignated warehouse is absolutely liable when a tornado
destroys the goods or when a thief steals them.