Excerpt from Treatise of the Law of Torts by Thomas McIntyre Cooley (Callaghan, 1888)

Personal immunity. The right to one's person may be said to be a right of complete immunity: to be let alone. The corresponding duty is, not to inflict an injury, and not, within such proximity as might render it successful, to attempt the infliction of an injury. In this particular the duty goes beyond what is required in most cases; for usually an unexecuted purpose or an unsuccessful attempt is not noticed. But the attempt to commit a battery involves many elements of injury not always present in breaches of duty; it involves usually an insult, a putting in fear, a sudden call upon the energies for prompt and effectual resistance. There is very likely a shock to the nerves, and the peace and quiet of the individual is disturbed for a period of greater or less duration. There is consequently abundant reason in support of the rule of law which makes the assault a legal wrong, even though no battery takes place. Indeed, in this case the law goes still further and makes the attempted blow a criminal offense also.