class of potential plaintiffs was limitless, the court undertook to define and circumscribe the class to whom the defendant owed a duty. (Thing v. La Chusa, supra, 48 Cal.3d 644, 652; Dillon v. Legg, supra, 68 Cal.2d 728, 733-735.)
In determining liability for negligence, we begin always with the command of Civil Code section 1714, subdivision (a): “Everyone is responsible, not only for the result of his willful acts, but also for an injury occasioned to another by his want of ordinary care or skill in the management of his property or person, except so far as the latter has, willfully or by want of ordinary care, brought the injury upon himself.” In the absence of a statutory provision limiting this rule, exceptions to the general principle imposing liability for negligence are recognized only when clearly supported by public policy. (Rowland v. Christian (1968) 69 Cal.2d 108, 112 [70 Cal.Rptr. 97, 443 P.2d 561, 32 A.L.R.3d 496.) Amaya, Dillon, and Thing reflect a public policy exception which limits the right of a bystander who did not suffer physical injury and was not threatened with such injury to recover damages for the emotional distress the bystander suffered as a result of witnessing negligent conduct which caused physical injury to a third person. If any and all bystanders who witnessed the injury-causing event were permitted to recover for ensuing emotional distress, the defendant’s liability could be out of all proportion to the degree of fault. (Molien v. Kaiser Foundation Hospitals (1980) 27 Cal.3d 916, 922-923 [167 Cal.Rptr. 831, 616 P.2d 813, 16 A.L.R.4th 518]; Amaya v. Home Ice, Fuel & Supply Co., supra, 59 Cal.2d 295, 315.) Public policy therefore justified a limitation on the statutory right to recover damages for the emotional distress injury.
We agree with defendants that public policy considerations are relevant in determining whether a particular plaintiff may recover damages for emotional distress. This is true, however, whenever a plaintiff asserts that the negligent conduct of another breached a duty owed to the plaintiff. “The existence of duty is a question of law. (Richards v. Stanley (1954) 43 Cal.2d 60, 66-67 [271 P.2d 23].) ‘[L]egal duties are not discoverable facts of nature, but merely conclusory expressions that, in cases of a particular type, liability should be imposed for damage done.’ (Tarasoff v. Regents of University of California (1976) 17 Cal.3d 425, 434 [131 Cal.Rptr. 14, 551 P.2d 334, 83 A.L.R.3d 1166].)
“It is a fundamental proposition of tort law that one is liable for injuries caused by a failure to exercise reasonable care. We have said, however, that in considering the existence of ‘duty’ in a given case several factors require consideration including ‘the foreseeability of harm to the plaintiff, the degree of certainty that plaintiff suffered injury, the closeness of the connection between the defendant’s conduct and the injury suffered, the moral