G.R. No. 192956 , July 24, 2019.
Case Parties: (Referenced from the main decision) Various parties claiming title to a foreshore land.

FACTS

The core dispute in the main decision involved conflicting claims over a parcel of land classified as foreshore land. The ponencia, authored by Justice Reyes, applied the regalian doctrine to determine that the land, being part of the public domain, could not be privately owned, and thus neither party could assert a valid title. Justice Leonen, in his separate concurring opinion, agrees with the ultimate disposition to deny the petitions but seeks to clarify and refine the legal reasoning underpinning the application of the regalian doctrine and the constitutional framework governing alienable lands of the public domain.

ISSUE

The key issues addressed in Justice Leonen’s concurrence are: (1) whether the regalian doctrine is an absolute and fundamental tenet that presumes all lands belong to the State, and (2) what are the permissible modes for the State to utilize foreshore lands and other natural resources through agreements with private entities under the 1987 Constitution .

RULING

Justice Leonen concurs in the result but clarifies that the regalian doctrine is not an unqualified principle presuming all lands are State-owned. He traces its origin to Spanish feudal law and notes its significant modification, beginning with the American colonial period as recognized in Cariño v. Insular Government. The Cariño doctrine established that lands held by individuals under a claim of private ownership since time immemorial are presumed never to have been part of the public domain. This creates a critical exception, protecting property rights rooted in immemorial possession, even without paper titles, under the due process clause of the Constitution.
Furthermore, Justice Leonen emphasizes that the 1987 Constitution explicitly limits State ownership to “lands of the public domain,” thereby rejecting the broadest feudal interpretation of the regalian doctrine. Regarding the disposition of such lands, he highlights a pivotal constitutional shift. While the 1973 Constitution allowed the State to directly lease natural resources to private parties, Article XII, Section 2 of the 1987 Constitution now restricts the State to three specific modes when involving private entities: co-production, joint venture, or production-sharing agreements. Consequently, for foreshore lands—classified as alienable lands of the public domain—the State can no longer simply lease them under the Public Land Act ( Commonwealth Act No. 141 ) if the intent is for the exploration, development, or utilization of natural resources. Any such engagement must conform to the stricter constitutional frameworks of co-production, joint venture, or production-sharing agreements.