concurring and dissenting.
The majority seeks to insulate its analysis from critical scrutiny by maintaining that the result it reaches is dictated by the “clear and unambiguous” language of Section 204(1), of the Retirement Code (Code), 71 P.S. § 1725-204(1) (1962). The majority leaves unstated the fact that an ambiguity can be latent as well as patent.* When it is considered that the *321State did not have a category of part-time salaried employees at the time of enactment of the 1959 Code, the weakness of the majority’s primarily textual analysis of the Code becomes apparent.
The majority places considerable emphasis on the Code’s definition of “State employee,” contained in section 102(6)(a). 71 P.S. § 1825-102(6)(a) (1962) (repealed 1974). Based on this section’s exclusion of per diem and hourly employees only, the majority concludes that the legislature intended to make retirement benefits available on equal terms to full-time as well as part-time salaried employees. As noted by appellants, the utilization of part-time salaried employees was a circumstance which arose after the enactment of the Code in 1959. In fact, the record indicates that none of the named appellees was a part-time salaried State employee prior to 1959. Far from evidencing the legislature’s sweeping magnanimity, the absence of explicit statutory provisions governing retirement benefits for part-time salaried employees merely reflects the “historical milieu” in which the 1959 Legislature was acting. See 2A Sutherland, Statutes and Statutory Construction § 49.01, at 288 (4th ed. 1973) (historical context should be considered in construing a statute). When this contemporaneous historical context is weighed along with the Code’s total exclusion of part-time employees who work less than a specified number of days or hours, 71 P.S. § 1725-102(6)(a) (1962) (repealed 1974), it is impossible to accept the majority’s conclusion that the legislature intended to award credited service to part-time salaried employees at the same rate at which such credit is awarded to full-time salaried employees.
The fact that until 1969 the Board interpreted the Code in the manner now urged by appellees is of no moment. In so interpreting the Code, the Board was merely exercising its administrative discretion to meet an exigency not explicitly *322addressed by the Code. It seems fairly clear that an administrative agency may modify or even reverse its own interpretation of a statute, especially where, as here, the new interpretation is based upon the opinion of the Attorney General. See Sutherland, supra § 49.05, at 240. In such a situation, the new administrative interpretation should be applied prospectively only. Id. Therefore, in the present appeal, I would not permit the Board to apply its 1969 reinterpretation retrospectively so as to recalculate credited service based upon appellees’ pre-1969 salaried part-time employment. I would, however, allow the Board to apply its 1969 interpretation to appellee’s part-time salaried employment occurring after the date of this interpretation and until the effective date of the 1974 Retirement Code. 71 Pa.C.S.A. §§ 5101 et seq. (Supp.1978-79).
While I acknowledge the wisdom of the general rule that there should be some facial statutory ambiguity before a court considers extrinsic evidence of legislative intent, 1 Pa.C.S.A. § 1921(c) (Supp.1978-79), I do not believe that there should be slavish adherence to this principle where it is obvious that the result reached will be a clear distortion of the legislative purpose. See 2A Sutherland, Statutes and Statutory Construction § 48.01, at 182 (4th ed. 1973), citing, inter alia, Herren v. United States, 317 F.Supp. 1198 (S.D.Tex.1970). There is some justification in attempting to restrain judicial attempts to construe statutes as a judge may deem most advisable by imposing the “clear and unambiguous” language limitation. But where extrinsic evidence is critical to a true understanding of the “clear and unambigu*321ous” language of the statute, it should not be ignored. This is so, bee' ,ict; no matter how apparently clear the language may appear, words do not have intrinsic meanings and cannot be separated from the historical context in which they were written. See 2A Sutherland, supra § 45.02, at 4.