CASE 10: Republic v. Cu (G.R. No. L-3018, July 18, 1951)

Jus Sanguinis Principle

Citizenship is determined by bloodline. The Court ruled that if Cu’s parents were legally married, he was a Chinese citizen by virtue of his father’s nationality.

Jus Soli Principle (Not Applicable in the Philippines)

Citizenship is determined by place of birth. The Court reaffirmed that the Philippines follows jus sanguinis and not jus soli, meaning birth in the country does not automatically grant Filipino citizenship.

Presumption of Legitimacy (Article 164, Civil Code)

A child is presumed legitimate if born within a valid marriage. The Court presumed Cu’s parents were legally married absent clear proof to the contrary.

Election of Philippine Citizenship (1935 Constitution, Article IV, Section 1(4))

A person born of an alien father and a Filipino mother must elect Philippine citizenship upon reaching the age of majority. The Court ruled that Cu failed to elect Filipino citizenship, making him a Chinese citizen.

Burden of Proof in Citizenship Claims

The person claiming Philippine citizenship has the burden of proving their status. The Court found Cu’s evidence insufficient to establish his Filipino citizenship.

Requirements for Naturalization (Commonwealth Act No. 473, Section 7)

A petition for naturalization must be supported by the affidavits of at least two credible Philippine citizens who personally know the applicant and can attest to their qualifications. The Court ruled that Cu’s witnesses were unqualified.

Defective Naturalization Petition Voids the Application

If a petition for naturalization is not verified by qualified witnesses, it is void and cannot be amended or cured by substitution of witnesses.

Doctrine of Presumption of Foreign Citizenship

A person of mixed nationality is presumed to follow the father’s citizenship unless there is a valid election of Philippine citizenship. The Court ruled that Cu remained a Chinese citizen.

Competency of Witnesses in Naturalization Cases

Witnesses must be Philippine citizens who have known the applicant for the required residency period. The Court found Cu’s witnesses unqualified, making his application void.

Effect of a Court’s Finding of Citizenship in a Naturalization Case

A court ruling in a failed naturalization petition cannot confer citizenship. The Court reversed the lower court’s finding that Cu was a Filipino citizen.