SUBSTANTIVE OR PROCEDURAL NATURE OF PRIVATE INTERNATIONAL LAW RULES - 18 PJP 21 (2024)

RECOMMENDED CITATION: DELA PEÑA, Mark Angelo S. (2024), “Substantive or Procedural Nature of Private International Law Rules,” 18 PJP 21, available at <insert link> (last accessed on <date>).

ABOUT THE AUTHOR/S: Mark Angelo S. Dela Peña is a lawyer, court litigator, and law professor.

LAST REVISION: [None].


There has been a long, ongoing and continuing debate on the question of whether private international law rules are substantive or procedural in nature. My journal, of course, does not aim to end such debate as the capacity to do so belongs to experts in the field of civil law and remedial law. However, the following observations are respectfully submitted.

First, a substantive law in its broad sense is one that creates or abolishes a right. On the other hand, a procedural law in its broad sense is one that provides for the manner by which a right may be asserted or pursued. Justice Feria, in a dissenting opinion, once observed that substantive law is that part of the law which creates, defines, and regulates rights as opposed to objective or procedural law which prescribes the method of enforcing rights.[1]

The Good Justice continued to explain that what constitutes practice and procedure in the law is the mode or proceeding by which a legal right is enforced. In short, procedural law is that which regulates the formal steps in an action or judicial proceedings, the course of procedure in courts, the form, manner and order that proceedings should follow, and the form, manner and order of carrying on and conducting suits or prosecutions in the courts. These are done through their various stages and according to the principles of law and the rules laid down by the respective courts.[2]

While, for example, Philippine laws on succession provide the right of compulsory heirs to legitime,[3] the same laws also point to the application of the national law of a foreign decedent.[4] If properly pleaded and proved, such foreign law could result in a finding that it does not recognize the concept of legitime.[5] In other words, it is not private international law itself that provides for the rule on legitime; rather, it is civil law that creates such right. Nevertheless, the directive of the law to apply foreign law cannot, strictly speaking, be said to be one that creates a right.

Second, private international law rules merely point to the application of foreign law. If the foreign law points back to municipal law (i.e., in the case of the Philippines, Philippine law), the Philippine court should apply the substantive provisions of that municipal law in compliance with the theory of renvoi. In other words, the forum will, in proper cases and as a rule, have its hands tied and is under the legal obligation to apply the applicable substantive provisions provided for by foreign law in order to resolve the dispute. Again, in this sense, conflict of laws rules per se do not govern the issues of the case; rather, they merely guide the eyes of the court on what system of laws should apply.

Third, under the 1987 Constitution, only the Supreme Court has the power to promulgate rules regarding pleading, practice, and procedure. To say that private international law rules are strictly procedural in nature would oust the same from the ambit of the powers of Congress. In fact, most of the core choice of law principles observed in the Philippines are provisions of law such as those in the New Civil Code (NCC) and the Revised Penal Code (RPC).

Despite the unending debate on the substantive or procedural nature of conflict of laws rules, it may be safely argued that private international law principles are unique in nature; they are sui generis, so to speak. Their applications traverse the middle ground between both categories. While mere reference to foreign law appears to be procedural in nature, the application of that foreign law surely involves substantive rights.


[1] J. FERIA, Dissenting Opinion in Bustos v. Lucero (G.R. No. L-2068. March 08, 1949).

[2] 31 Cyc. Law and Procedure, Page 1153.

[3] See VDA. DE CLAUDIO v. ARAGON, 88 Phil. 107 (G. R. No. L-2920, January 23, 1951) [Per, J. Bautista, En Banc].

[4] CIVIL CODE, Article 16, Paragraph 2.

[5] AZNAR v. GARCIA, 117 Phil. 96 (G. R. No. L-16749, January 31, 1963) [Per J. Labrador, En Banc].