This is a proceeding to review an award of compensation made by the Industrial Accident Commission in favor of an injured employee. At the time the employee sustained his admittedly compensable injury, section 4661 of the Labor Code provided that “Where an injury causes both temporary and permanent disability, the injured employee is not entitled to both a temporary and permanent disability payment, but only to the greater of the two.” By an amendment effective as of September 15, 1945, the following proviso was added to section 4661: “except that where the temporary disability payment exceeds 25 per cent of the permanent disability payment the injured employee shall be paid 75 per cent of such permanent disability payment in addition to the temporary disability payment.” Thereafter the commission made its award allowing compensation pursuant to the terms of the amended statute, with the result that the award was greater than it would have been had the commission applied section 4661 as it read at the date of injury. Twelve additional cases arising from similar factual situations have been consolidated with this proceeding.
The two-fold question to be determined in this proceeding is whether the commission gave retrospective operation to the amended statute by applying it in a ease where the injury occurred prior to the amendment and, if so, whether such retrospective application was proper.
“A retrospective law is one which affects rights, obligations, acts, transactions and conditions which are performed or exist prior to the adoption of the statute.” (American States W. S. Co. v. Johnson, 31 Cal.App.2d 606, 613 [88 P.2d 770] ; Ware v. Heller, 63 Cal.App.2d 817, 821 [148 P.2d 410] ; 23 Cal.Jur. 628.) Respondent commission contends, however, that in making its award in accordance with section 4661 as amended, it gave only prospective operation to the amendment. It is argued that the statute deals with the sub*392ject of disability to which the injury is a mere antecedent fact, that there was no right to or correlative obligation for permanent disability compensation at the time of injury but that such right or obligation arose only after the disability was manifest and its existence determined by the commission, and that consequently no existing rights or obligations were affected by application of the amendment even though the injury occurred before its adoption. With this reasoning we cannot agree.
The prior industrial injury was not a mere antecedent fact relating to the permanent disability ensuing therefrom; on the contrary, it was the basis of the right to be compensated for such disability. This is recognized by the amendment itself which begins with the recital “Where an injury causes both temporary and permanent disability.” Moreover, it is elementary that an industrial injury is the foundation of rights and liabilities under workmen’s compensation laws. (See Lab. Code, § 3600.) It may be true that, with respect to certain procedural matters, proceedings for permanent disability compensation are viewed as separate and distinct from proceedings for temporary disability compensation. (See Gobel v. Industrial Acc. Com., 1 Cal.2d 100 [33 P.2d 413] ; Cowell L. & C. Co. v. Industrial Acc. Com., 211 Cal. 154 [294 P. 703, 72 A.L.R. 1118].) It does not follow, however, that the “cause of action” for permanent disability is separate and distinct from the original industrial injury. (Lab. Code, § 5303.) The employee was entitled to compensation not merely because he became permanently disabled, but because that disability resulted from an injury in the course of and arising out of his employment.
Since the industrial injury is the basis for any compensation award, the law in force at the time of the injury is to be taken as the measure of the injured person’s right of recovery. The 1945 amendment of section 4661 increased the amount of compensation above what was payable at the date of the injury, and to that extent it enlarged the employee’s existing rights and the employer’s corresponding obligations. The amendment is therefore clearly substantive in character, and the commission, by applying it in the present proceedings, gave it a retrospective operation.
The authorities support the conclusion that a statute changing the measure or method of computing compensation for disability or death is given retrospective effect when applied *393to disability or death resulting from an injury sustained before the effective date of the statute. (Holmberg v. City of Oakland, 55 Cal.App. 270, 272 [203 P. 167] ; United Iron Works v. Smethers, 159 Okla. 105 [14 P.2d 380] ; Lynch v. State, 19 Wn.2d 802 [145 P.2d 265] ; Virden v. Smith, 46 Nev. 208 [210 P. 129] ; Polk v. Western Bedding Co., 145 Pa.Super. 142 [20 A.2d 845]; Quilty v. Connecticut Co., 96 Conn. 124 [113 A. 149]; Stanswsky v. Industrial Commission, 344 Ill. 436 [176 N.E. 898] ; see Hendrickson v. Industrial Acc. Com., 215 Cal. 82, 84 [8 P.2d 833] ; Hyman Bros. B. & L. Co. v. Industrial Acc. Com., 180 Cal. 423, 424 [181 P. 784]; Chaney v. Los Angeles County Retirement Bd., 59 Cal.App. 2d 413 [138 P.2d 735].) The only case cited in support of the contrary view is Talbot v. Industrial Ins. Com., 108 Wash. 231 [183 P. 84, 187 P. 410]. It is sufficient to note that in a subsequent case the same court which decided it stated that the Talbot case “did not say that the allowance of the increased payment was in ‘no sense’ a retroactive application of the amendatory act, but simply said that so to apply the amendment did not amount to giving it a retroactive effect contrary to the intention of the legislature.” (Lynch v. State, 19 Wn.2d 802 [145 P.2d 265, 268].)
It is an established canon of interpretation that statutes are not to be given a retrospective operation unless it is clearly made to appear that such was the legislative intent. (Jones v. Union Oil Co., 218 Cal. 775 [25 P.2d 5]; In re Cate, 207 Cal. 443 [279 P. 131] ; Pignaz v. Burnett, 119 Cal. 157 [51 P. 48].) It is contended upon behalf of respondents that this rule of statutory construction has no application to procedural statutes, and that section 4661 relates solely to matters of procedure or remedy. Feckenscher v. Gamble, 12 Cal.2d 482 [85 P.2d 885], City of Los Angeles v. Oliver, 102 Cal.App. 299 [283 P. 298], San Bernardino County v. Industrial Acc. Com., 217 Cal. 618 [20 P.2d 673], and Davis & McMillan v. Industrial Acc. Com., 198 Cal. 631 [246 P. 1046, 46 A.L.R 1095], are relied upon in support of the contention. In those eases, with one exception, it was held that the language of the statutes showed that the Legislature intended them to be applied retroactively, and the court was concerned mainly with the question of whether the Legislature has power to give those laws such retroactive effect. Since the question of the constitutionality of retroactive legis*394lation and the question of the applicability of a rule of statutory construction are distinct (Ware v. Seller, 63 Cal.App.2d 817, 821 [148 P.2d 410]), these cases are not in point.
Davis & McMillan v. Industrial Acc. Com., supra at page 638, contains language, quoted from-36 Cyclopedia of Law, page 1201, to the effect that the presumption against retrospective construction does not apply to statutes relating merely to remedies and modes of procedure. (See, also, Crawford, The Construction of Statutes, p. 581.) A different theory is offered to reach the same result in Morris v. Pacific Electric Ry. Co., 2 Cal.2d 764, 768 [43 P.2d 276], wherein this court stated that procedural changes “operate on existing causes of action and defenses, and it is a misnomer to designate them as having retrospective effect.” (See, also, Estate of Patterson, 155 Cal. 626, 638 [102 P. 941, 132 Am.St.Rep. 116, 18 Ann.Cas. 625, 26 L.R.A.N.S. 654] ; Ware v. Seller, 63 Cal.App. 2d 817, 825 [148 P.2d 410].) In other words, procedural statutes may become operative only when and if the procedure or remedy is invoked, and if the trial postdates the enactment, the statute operates in the future regardless of the time of occurrence of the events giving rise to the cause of action. [Blyer v. Hershman, 156 Misc. 349 [281 N.Y.S. 942, 944].) In such cases the statutory changes are said to apply not because they constitute an exception to the general rule of statutory construction, but because they are not in fact retrospective. There is then no problem as to whether the Legislature intended the changes to operate retroactively.
This reasoning, however, assumes a clear-cut distinction between purely “procedural” and purely “substantive” legislation. In truth, the distinction relates not so much to the form of the statute as to its effects. If substantial changes are made, even in a statute which might ordinarily be classified as procedural, the operation on existing rights would be retroactive because the legal effects of past events would be changed, and the statute will be construed to operate only in futuro unless the legislative intent to the contrary clearly appears. (Jones v. Union Oil Co., supra, 218 Cal. 775, 777 [change in procedure to obtain judgment liens]; In re Cate, supra, 207 Cal. 443, 448 [change in reinstatement procedure by enactment of State Bar Act] ; Pignaz v. Burnett, supra, 119 Cal. 157, 160 [change in time to appeal].) The argument that the statute in this case is a procedural law to which the general rule of statutory construction does not apply is but a different statement of the respondent commis*395sion’s original contention that it did not give a retrospective application to the amendment. As we have heretofore concluded, the amendment of section 4661 is substantive in its effect, and its operation would be retroactive, since it imposes a new or additional liability and substantially affects existing rights and obligations.
We turn now to the contention that the Legislature intended to give retrospective operation to the 1945 amendment of section 4661. That intention does not appear on the face of the amendment since no express provision was made for its application to cases involving prior injuries. Respondents urge, however, that such intention appears by necessary implication.
It is argued that since the provisions of the Workmen’s Compensation Act are to be liberally construed to extend their benefits to injured persons (Lab. Code, § 3203), the legislative intention that the amendment should operate retrospectively must be implied. No authority is cited for this novel doctrine which would require the court to ignore the rule against retroactive operation with respect to statutes increasing benefits to persons favored by remedial legislation. The rule of liberal construction and the rule that statutes should ordinarily be construed to operate prospectively are neither inconsistent nor mutually exclusive. They relate to different aspects of the interpretation of statutes, and are found in most of the codes, including the Labor Code. (Civ. Code, §§ 3, 4; Code Civ. Proc., §§ 3, 4; Pen. Code, §§ 3, 4; Lab. Code, §§ 4, 3202.) It would be a most peculiar judicial reasoning which would allow one such doctrine to be invoked for the purpose of destroying the other. It seems clear, therefore, that the legislative intent in favor of the retrospective operation of a statute cannot be implied from the mere fact that the statute is remedial and subject to the rule of liberal construction. (See Virden v. Smith, supra [Nev.], 210 P. 129, 130.)
It is also argued that the legislative intent to extend the benefits of the amendment to previously injured workmen must be implied from the fact that the Legislature could not have intended to differentiate between workmen injured before and after the effective date of the amendment. The argument is not persuasive. Every change in the law brings about some difference in treatment as a result of the prospective operation of the amendment. Moreover, the injustice that *396might be suffered by an employer if the amendment were applied retrospectively would afford ample basis for an intentional difference in treatment of workmen injured before and after adoption of the amendment.
Finally, it is argued that the amendment was motivated by the need for an increase in disability benefits due to war conditions and economic crises, that such necessity applies to disabled workmen without regard to the date of their injury, and that therefore a retrospective operation must have been intended. There is nothing on the face of the statute which indicates that the economic effect of the war motivated its enactment, and the amendment was not made a part of a general increase in compensation for all compensable injuries, which might indicate an intent to provide for such unusual conditions. In Schmidt v. Wolf Contracting Co., 269 App. Div. 201 [55 N.Y.S.2d 162], affd. 295 N.Y. 748 [65 N.E.2d 568], relied upon by respondents, it was held that a statute increasing both temporary and permanent disability payments for a limited period was intended to operate retrospectively. The court reached its conclusion on the ground that the statute contained an introductory recital “Because of existing conditions due to war” which would have been surplusage had the Legislature intended to restrict the increase to employees injured after the effective date of the amendment. The implication from that decision is clear that if, as in the present case, the statute did not contain the quoted language it would have been construed to apply prospectively only.
Our conclusion is that it does not clearly appear from the language of the amended statute, or by necessary implication, that the Legislature intended it to apply in cases where the injury occurred before the effective date of the enactment. On the contrary, it must be assumed that the Legislature was acquainted with the settled rules of statutory interpretation, and that it would have expressly provided for retrospective operation of the amendment if it had so intended. Accordingly the commission improperly gave a retrospective effect to the amendment by applying it to claims arising out of injuries occurring prior to the date of its enactment.
The awards are annulled and the causes are remanded for further proceedings in accordance with this opinion.
Shenk, J., Edmonds, J., Traynor, J., Schauer, J., and Spence, J., concurred.