"[W]hen the avoidance of foreseeable harm requires a defendant to control the conduct of another person, or to warn of such conduct, the common law has traditionally imposed liability only if the defendant bears some special relationship to the dangerous person or to the potential victim . . . [T]he relationship between a therapist and his patient satisfies this requirement. . ."

"[U]nder the common law, as a general rule, one person owed no duty to control the conduct of another . . ."

"[A] duty of care may arise from either `(a) a special relation . . . between the actor and the third person which imposes a duty upon the actor to control the third person's conduct, or (b) a special relation . . . between the actor and the other which gives the other a right of protection.'"

	control conduct
	/------------>	Threat ("third person")
"actor" ("defendant")
	\------------>	potential victim ("other")
	warn