Under Philippine law, particularly the Family Code of the Philippines, legitimate children are defined and protected under specific provisions. In order to understand who qualifies as legitimate children under Philippine law, it’s essential to go through the applicable rules and legal concepts governing paternity, filiation, and the legitimacy of children.

Legal Basis: Family Code of the Philippines

The Family Code of the Philippines, primarily Articles 163 to 174, governs the legal concepts related to paternity, filiation, and legitimacy of children. The following outlines the key provisions:

Article 163: Definition of Filiation

Filiation is defined as the relationship between a child and their parents. The law recognizes two types of filiation:

Legitimate filiation
Illegitimate filiation

Article 164: Definition of Legitimate Children

Children are deemed legitimate if they are:

Conceived or born within a valid marriage; or
Born during a marriage that is later annulled or declared void.

Thus, if a child is born under the above conditions, they are considered legitimate under Philippine law.

Determining Who are Legitimate Children

1. Children Conceived or Born During a Valid Marriage (Article 164)

Children born to parents who are married to each other at the time of conception or birth are considered legitimate.
Legitimacy is automatically granted by law without the need for a judicial declaration.

2. Children Born to a Voidable Marriage (Article 54, in relation to Article 164)

If a child is born of a marriage later annulled by the court, the child remains legitimate provided the marriage was entered into in good faith by at least one of the parties.
For example, if a spouse marries in good faith, and the marriage is later annulled, the legitimacy of children born during that marriage is preserved.

3. Children Born of a Void Marriage (Article 54)

A void marriage does not produce legal effects; however, children conceived or born of a marriage that is declared void under specific legal grounds (e.g., psychological incapacity or lack of marriage license) may still be considered legitimate.
The Family Code allows for legitimacy if both parents were in good faith at the time of the marriage, under the "putative marriage" doctrine, thereby protecting children from losing their legitimate status due to the parents' marital status.

4. Children Conceived by Artificial Insemination (Article 164, in relation to Article 165)

Children conceived through artificial insemination with the consent of the spouse of the mother are considered legitimate.
The law provides legitimacy in cases of assisted reproduction as long as both parents (the mother and her husband) consented to the procedure, thereby acknowledging the paternity of the child.

Presumptions of Legitimacy

Under Article 167, the law presumes that:

A child born to a married woman is presumed to be the child of her husband unless there is evidence to the contrary.
The presumption of legitimacy is rebuttable but can only be overturned through a judicial action filed by the husband, or in some cases, the heirs, proving that he is not the child’s father.

Rebutting the Presumption of Legitimacy

The presumption of legitimacy can be challenged within the period provided by law (usually within 5 years), and only in limited circumstances.
A court action must be filed to rebut legitimacy, typically requiring proof of non-access by the husband or other conclusive evidence that the husband is not the father.

Rights of Legitimate Children

Legitimate children enjoy the following rights under the Family Code:

Right to Inherit: Legitimate children are compulsory heirs and have a legal right to inherit from their parents’ estates.
Right to Bear Surname: Legitimate children automatically bear the surname of their father.
Right to Parental Support and Legitimacy: Legitimate children have a right to financial support from both parents and to the legal recognition of their filiation.

Evidentiary Rules for Proving Legitimacy (Article 172)

The following forms of evidence can establish legitimate filiation:

Record of Birth: The child’s birth certificate showing that the parents were married at the time of birth.
Public Records: Official records, family records, and other public documents recognizing the child as legitimate.
Parental Acknowledgment: Written acknowledgment by the parent, or any similar documents where the father recognizes the child as legitimate.

In cases where no public record exists, legitimate filiation can also be proved by:

Private Letters and Declarations of the parents admitting the child’s legitimacy.
Continuous and Unmistakable Possession of Status as a legitimate child, such as treatment by the parents in a manner that openly acknowledges the child’s legitimacy.

Challenging Legitimacy

Legitimacy challenges must be initiated through a proper court proceeding.
An action to impugn the legitimacy of a child can only be filed by specific individuals (usually the husband or heirs), and the Family Code imposes a limited timeframe for such actions.

Conclusion

Under the Family Code of the Philippines, legitimate children are defined as those born to parents who are legally married at the time of the child's conception or birth, those born to marriages later annulled, and, under certain conditions, children of void marriages. The law presumes legitimacy to protect the child's rights to inheritance, parental support, and other privileges associated with legitimate status. The law provides means to challenge legitimacy but requires strict adherence to procedural rules and evidence requirements.