This is an appeal from a judgment of the Court of First Instance of Cotabato, the Hon. Juan A. Sarenas, presiding, approving the petition for naturalization of petitioner Yu Singco, a Chinese. citizen. Opposition to the petition was presented by the Government on the ground that "he had lived an immoral life by maintaining two Chinese wives and had formerly illicit relationship with one Pura Ortuoste, with whom he had begotten three children." There is no evidence of the supposed illicit relations between Pura Ortuoste and the petitioner. However, there is evidence to the effect that a certain Concepcion Cua had relations with the petitioner, as a result of which five children were born to her. Petitioner did not deny the relationship or that the children were his. He even admitted that he had lived in the same home with her and had been giving her money, although the excuse he gives is that he had received help from Cua's father, when still living with the latter. The petitioner now has ten children with Chua Hoc Ty whom she married in Amoy, China in 1924. As to all other qualifications, there was sufficient evidence that petitioner was fully qualified for naturalization.

The trial court held:

"* * *. There must be some grain of truth in this piece of evidence that cannot be entirely ignored, especially in the case of Concepcion Cua with whom, it is alleged, the petitioner has begotten some children. But the court, however, believes that such love affair if at all true, did exist once upon a time when the petitioner was still a young married man. This case is not unusual in life and is true in any part of the world. The allegation with respect to the regular support and maintenance that the petitioner is extending to his alleged children with Concepcion Cua, were it a fact, militates more in his favor than not, because it only goes to prove the grandeur of heart and consciousness of a grace responsibility on the part of the petitioner. Not many people, the court has observed, are gifted with such a noble human sentiment and gentlemanliness."

On this appeal, the Solicitor General contends that the petitioner has not conducted himself "in a proper and irreproachable manner during the entire period of his residence in the Philippines * * *", as required by section 2 of the Revised Naturalization Law. We are constrained to uphold this contention. What constitutes "proper and irreproachable conduct" within the meaning of the law must be determined, not by the law of the country of which the petitioner is a citizen (polygamy is allowed in China), but by the standards of morality prevalent in this country, and these in turn by the religious beliefs and social concepts existing therein. This country is predominantly Catholic and universally Christian in religious belief. Both seduction and bigamy are punished as crimes, and while seduction is a private crime and illegitimates declared legal heirs, a man and a woman living together as husband and wife, if known to be unmarried, are in general despised and avoided in society, even if not considered social outcasts. Society may pardon the sins of their members, but such pardon should not be confused with approval. In the case at bar, we disagree with the conclusions of the trial court and hold that as petitioner had previously lived with another woman with whom he has had five children and subsequently abandoned them, marrying another, his conduct can under no circumstances be considered "proper and irreproachable" within the meaning of the law, even if he actually gives support to his children.

The judgment appealed from is, therefore, hereby reversed and the petition for naturalization denied. So ordered.

Paras, C. J., Pablo, Bengzon, Padilla, Tuason, Reyes and Bautista Angelo, JJ., concur.