. In 1921, José Ayala Rodriguez, while married to Brígida Acevedo, lived in concubinage with Mariana Ginés who at that time was an adolescent 15 years old. Subsequently, late in 1926, José Ayala Rodriguez divorced his wife Brígida Acevedo and upon liquidation of the community partnership, two urban properties in the town of Manatí were adjudicated to him, as it appears from deed No. 71 of liquidation and partition of community property, executed on August 16, 1927 before Notary José E. Díaz. José Ayala Rodriguez continued to live with his concubine Mariana Ginés until his death. The trial court concluded: “That, notwithstanding the absence of agreement between them for the partition of the property acquired during the concubinage, Mariana Ginés, in addition to performing the duties incidental to her status of concubine, also contributed from time to time with other labor of less importance which in some way helped José Ayala Rodriguez in the operation of his business.”
*239By deed No. 38 of May 9, 1941 executed before Notary José E. Díaz, of Manatí, Puerto Rico, José Ayala' Rodriguez, of full age, divorced, a farmer, and a resident of Manatí, adopted minor Luis Norberto Ginés Maldonado with the previous consent of his parents and ratification by the former District Court of Arecibo. In the deed of adoption it was stated: “That as a result and by virtue of this adoption, the adopter grants to the said adopted child the right to bear his surname and all such rights as the laws of Puerto Rico grant to the children as if they were born of a lawful marriage, with the limitations prescribed by the existing Civil Code, the adopter stating that he is in the full enjoyment of all his civil rights and that he has no legitimate, legitimized, or natural children of any kind, and that he is over 45 years of age.”
The adopter, José Ayala Rodriguez, died on February 2, 1945, and his mother, Josefa Rodríguez Espino, was declared by order of August 24, 1945 of the former District Court of Arecibo “sole and universal heir ab intestato of her legitimate son, José Ayala Rodríguez.” The said Josefa Rodríguez Es-pino had died on June 24, 1945, that is, before being declared universal and sole heir of her son. The defendants-appellees herein form the intestate succession of the said Josefa Rodriguez Espino, according to the declaration of the former District Court of Arecibo of 'December 5, 1945.
On October 2, 1952, the plaintiffs, Mariana Ginés and Luis Norberto Ayala Ginés, filed in the Superior Court of Puerto Rico, Arecibo Part, a civil action for recognition of their respective rights within the actual partnership created by the concubinage and by virtue of the adoption by the deceased, José Ayala Rodriguez.
On February 23, 1955, the trial court rendered judgment on both questions declaring, as respects Mariana Ginés, “That the work performed by Mariana Ginés to help her paramour, José Ayala Rodriguez, in the operation of his business, was justly offset by the property which the latter *240recorded in her name when he purchased it from his brother [sic] Miguel by deed executed on April 10, 1942, and by the share which corresponded to her from the selling price of two urban properties situated in Manatí, as it appears from the deed executed on June 20, 1946,” and as respects the adopted child, “that on the date of the adoption of Luis Norberto Ayala Ginés, the well-established rule of our Supreme Court was that the adoptee only had the right to the inheritance left upon the death of the adopter, provided the rights of the heirs qualified as legitimate or forced heirs were not prejudiced; but since in this case upon the death of José Ayala Rodriguez in 1945 there was an ascendant, namely, his mother Josefa Rodríguez Espino, the plaintiff did not acquire any right in the inheritance, if it were so recognized since the exclusive right of the said ascendant would have been prejudiced.” It therefore dismissed the complaint.
In their petition for review before this Court, the plaintiff s-appellants assign the following error: (1) The respondent court “committed gross and manifest error of law in declaring that Luis Norberto Ayala Ginés, as adopted child, had no right to inherit from his father, José Ayala Rodriguez, upon the latter’s death on February 2, 1945.”
1. Regarding the question of the adopted child, the law applicable to the case is § § 132 and 133 of the Civil Code of 1930, which provided:
“Section 132. — Adoption shall in no case injure the rights belonging to forced heirs, which shall remain as though the adoption had not taken place.
“Section 133. — The person adopted shall enjoy in the family of the adopter the rights and duties and consideration of a legitimate child, with the exception noted in the preceding section.”
In applying these two sections, the trial court relied on our previous interpretation of those sections in the decision in Ex parte Lugo, 64 P.R.R. 826, 828, and 833 (Todd, Jr. and *241Travieso; De Jesús and Snyder, concurring; April 25, 1945). This case, overruled to a certain extent our previous decisions in the cases of Ex parte Ortiz, 42 P.R.R. 339, 341, and 344 (Wolf, 1931), and Bardeguez v. Bardeguez, 48 P.R.R. 692, 697 (Córdova Dávila, 1935). The case of Ex parte Lugo, supra, was in turn overruled by Sosa v. Sosa, 66 P.R.R. 573, 584 (Córdova Díaz; Todd, Jr., dissenting; July 26, 1946).
In the cases of Ex parte Ortiz and Bardeguez v. Bardeguez, supra, we arrived at the correct conclusion that the adopted child was a real forced heir. Such conclusion is absolutely correct, considering the civil kinship of agnatic category produced by the adoption. In the last case of Sosa v. Sosa, supra, we arrived at the conclusion that the adopted child’s right to inherit could not prejudice the preferential right of the forced heirs.
Mr. Justice Roberto Todd, Jr., in dissenting from the opinion of the majority in the last case of Sosa, in an opinion of November 5, 1946, pp. 587-88, stated the following: “I dissent from the opinion of the majority also, because although the courts, in construing statutes, may, as stated by Judge Holmes, legislate ‘interstitially,’ in my opinion they should refrain from so doing whenever the statute is so defective as to require for its construction and application judicial legislation every time a case comes up on said question. And such is the case with the adopted children in Puerto Rico in view of the decision that they are, in effect, legitimate children or at least are regarded as their equals. In so far as their hereditary portion is concerned, if the adopted child is like a legitimate child, said portion should be uniform at all instances. But such is not the case according to the opinion of the majority. It depends on whether the forced heirs are prejudiced and in order not to prejudice them the courts, and not the law, then come into play to determine in each case the amount of said portion. We have reached the maximum as to legislating judicially.
*242“Due to the changes that take place in this court — recently quite often — and the possibility of different opinions in the future as to the disputed and uncertain hereditary rights of adopted children, in the testate as well as in the intestate succession, it is my opinion that the Legislature of Puerto Rico should amend all those Sections of our code relating to adopted children in order to clearly define those rights. Otherwise, the uncertainty shall prevail and the courts shall continue legislating.”
It seems that the Legislative Assembly of Puerto Rico was impressed by this urgent call to clarify the rule because six months later it enacted Act No. 353 of May 13, 1947 (Sess. Laws, p. 680), with immediate effect, declaring that “the person adopted shall enjoy in the family of the adopter the rights and duties and consideration of a legitimate child,” and expressly repealing § 132, which established the rule that the adoption did not impair the rights of the forced heirs.
We therefore have before us what in civil law is known as a construing act, with implied retroactive effect, in force as of the date of the act thereby interpreted., 1-1 Castán, De-recho Civil, Común y Foral 409 (9th ed. by Instituto Editorial Reus, 1955). As well stated by Castán, “it is not necessary that the retroactivity provision be express; it shall-be sufficient if the purpose of the lawmaker appears evident from the meaning and purpose of the act.”
On this same point, Puig Peña states as follows: • “The formulation of the principle of irretroactivity never presupposes, as we have said, the impossibility that subsequent acts may have at times a retroactive character, affecting by their text the judicial relations arising under the former act. These exceptions to the retroactive principle arise in the following situations... (B) Whenever the lawmaker makes laws which by their nature and essence presuppose the retro-activity. — This occurs, above all, with the so-called construing acts, generally enacted to remove some doubt which may have *243arisen in the application of the former text. This assumption, in fact, should not pose any problem since we are not concerned here with a contradiction between the former act and the construing act, but with a mere rule clarifying and explaining the former.” II-1 Puig Peña, Tratado de Derecho Civil Español 440-41 (ed. by Editorial Revista de Derecho Privado, 1957).
• As may be seen, in the case of a construing statute — that which clarifies some point of a former statute — the judge is not faced with a problem of application of an act but with a problem of interpretation. In the American law this is regarded as a search for the post legislative intention. We know the importance which in American law is attached to this post legislative intention — some times called legislative interpretation of a former statute — in determining the true scope of the original statute, particularly when it is almost contemporaneous with the contrary judicial construction. 2'Sutherland, Statutory Construction 526-28, § 5110.
• Every rule in law has its history, its sense, its particular aura, and it is the judicial duty to extract its rationale from its origin. Originally, the adoption was one of the political, social, and even economic means employed by the patriciate to achieve the aggrandizement of their houses. Castán comments an exceptional case of adoption: that of Augustus who caused the Senate to proclaim him the adopted son of Julius Caesar in order to inherit the empire. Marcus Tulius — a prominent pseudonym almost forgotten in the Spanish juridical bibliography — comments another exceptional case of adoption, that of Don Sancho el Fuerte and Don Jaime el Conquistador, two kings who adopted each other in order to inherit each other and thus expand their privileges and prerogatives.
In Roman law the picture of agnation comprised all those persons foreign to the family, grouped around the potestas of the paterfamilias, such as the adopted children, the natural *244children, and the wife. As a question of historical reality, the adopted children had a preferential right over the legitimate children in the father’s inheritance.
Leyes de Partida sought to remedy the injustice which had been consecrated in the Roman law and in the feudal law against the legitimate children and in favor of the adopted children by providing for the concurrence of the adopted children (adoption) and the legitimate children in the father’s inheritance. The Spanish Civil Code prohibited the adoption by those having legitimate or legitimized children, and if there were none, it prohibited the right of inheritance between the adopter and the adopted child, unless the adopting parent shall have agreed in the deed of adoption to institute the person adopted as his heir (§ 177).
Although our Code originally adopted the prohibition to adopt by those having legitimate or legitimized children, it did not adopt the prohibition of the adopted child to inherit from his adopter. Hence, § § 131 and 132 of our Code, as they stood in 1945, must be construed as recognizing the right of the adopted child to inherit. Since our Code did not permit the adoption by those having legitimate or legitimized children, the phrase employed in § 132, before the latter was repealed, to the effect that “adoption shall in no case injure the rights belonging to forced heirs, which shall remain as though the adoption had not taken place,” is confined to the concurrence of the adopted child with the other agnates, namely, the duly acknowledged natural children and the widow, each with a fixed share and without exclusion in the suc-cessory order, and as respects this share and such exclusion in the successory order, it was necessary to maintain them in the same force as if the adoption had not taken place.
However, the only other forced heir is the adopter’s mother, but she has no right in the successory order if there are legitimate children, and, incidentally, the status enjoyed by the adopted child, by civil kinship, expressly declared by *245law, is that of a legitimate child, which excludes all other' heirs with the exception of those considered as agnates. Our statute in 1945 did not prohibit the adoption whenever there were ascendants, but when there were legitimate or legitimized children. This shows that if there are living ascendants, the adopter could grant his civil kinship to the adopted child, and the latter would be entitled to the inheritance with the same right as a legitimate child. This conclusion is reaffirmed once again by the enactment of Act No. 353 of May 13, 1947, which by repealing § 132 eliminates every reference to the prejudice of the right of the forced heirs, which in our opinion is a legislative interpretation contrary to our criterion in the last case of Sosa v. Sosa, whereby we sought to exclude the adopted children from the legitimate share whenever they concurred with other forced heirs.
In view of the doctrinal complex formed by five opinions quite contradictory among themselves and of a quasi-con-^ temporaneous construing act, in clear contradiction of the rule laid down by this Court in the last case of Sosa v. Sosa,' we ought to lay down a new rule on this litigious question and declared that according to § § 132 and 133 of the Civil Code of Puerto Rico, as it stood in 1945, the status of an adapted , child in the successory order is that of a legitimate child,> ■' with all the successory rights corresponding to a, legitimate . child, and that the phrase employed in § 132 in the sense that, “the adoption shall in no case injure the rights belonging to, forced heirs,” does not import an exclusion of the legitimate right to the inheritance of the adopting parent whenever there are forced ascendants, but a concurrence to the inhere •• itance with the legitimized natural children and the widow, and that the shares of the latter in the inheritance would be the same as if the adoption had not taken place.
It is clear that the purpose of the modern legislation on adoption is to eliminate the privilege of sole heir enjoyed by . *246the adopted child as against the legitimate children of the adopter, permitting the concurrence of the adopted child, as another child, with the other legitimate children — case of Puerto Rico, Act No. 100 of May 6,1948 (Sess. Laws, p. 228), and, Act No. '86 of June 15, 1953 (Sess. Laws, p. 304) — and with the acknowledged natural and illegitimate children and the widow.
This being so, there is no question that the trial court erred in applying the case of Ex parte Lugo, supra, and denying to the adopted child the right to inherit the entire hereditary estate, to the exclusion of the adopter’s mother.