In Bradley v. Appalachian Power Co., 163 W.Va. 332, 256 S.E.2d 879 (1979), the Court adopted the principle of comparative negligence and held that "a party is not barred from recovering damages in a tort action so long as his negligence or fault does not equal or exceed the combined negligence or fault of the other parties involved in the accident." However, the Court also stated that "before any party is entitled to recover, it must be shown that the negligence of the defendant was the proximate cause of the accident and subsequent injuries. The same is true of contributory fault or negligence. Before it can be counted against a plaintiff, it must be found to be the proximate cause of his injuries. " Bradley, 163 W.Va. at 342-343, 256 S.E.2d at 885. The Court outlined the formula for an initial determination of whether a decision should be considered retroactive or prospective, as follows: In determining whether to extend full retroactivity, the following factors are to be considered: First, the nature of the substantive issue overruled must be determined. If the issue involves a traditionally settled area of law, such as contracts or property as distinguished from torts, and the new rule was not clearly foreshadowed, then retroactivity is less justified. Second, where the overruled decision deals with procedural law rather than substantive, retroactivity ordinarily will be more readily accorded. Third, common law decisions, when overruled, may result in the overruling decision being given retroactive effect, since the substantive issue usually has a narrower impact and is likely to involve fewer parties. Fourth, where, on the other hand, substantial public policy issues are involved, arising from statutory or constitutional interpretations that represent a clear departure from prior precedent, prospective application will ordinarily be favored. Fifth, the more radically the new decision departs from previous substantive law, the greater the need for limiting retroactivity. Finally, the Court will also look to the precedent, of other courts which have determined the retroactive/prospective question in the same area of the law in their overruling decisions.