It is based on the policy against
multiplicity of suits,[1] whose primary objective is to avoid unduly
burdening the dockets of the courts.Speaking through Justice
J.B.L. Reyes, the Supreme Court in Aguila v. J.M. Tuason & Co., Inc.[2] held that:
Public policy is firmly set against unnecessary multiplicity of suits; the rule of res judicata, like that against splitting causes of action, are all applications of the same policy, that matters once settled by a Court's final judgment should not thereafter be invoked against. Relitigation of issues already settled merely burdens the Courts and the taxpayers, creates uneasiness and confusion, and wastes valuable time and energy that could be devoted to worthier cases. As the Roman maxim goes, Non bis in idem.[3] (Emphasis supplied.)
[1] Cruz v. Court of Appeals, 369 Phil. 161, 170-171 (1999).
[2] 130 Phil. 715, 720 (1968).
[3] Id. at 720.