Remedial Law; Immutability of judgment. Under the doctrine of immutability of judgment, a decision that has acquired finality becomes immutable and unalterable, and may no longer be modified in any respect, even if the modification is meant to correct erroneous conclusions of fact and law, and whether it be made by the court that rendered it or by the Highest Court of the land. Any act which violates this principle must immediately be struck down. This doctrine has a two-fold purpose, namely: (a) to avoid delay in the administration of justice and thus, procedurally, to make orderly the discharge of judicial business; and (b) to put an end to judicial controversies, at the risk of occasional errors, which is precisely why courts exist. Controversies cannot drag on indefinitely. The rights and obligations of every litigant must not hang in suspense for an indefinite period of time. The doctrine is not a mere technicality to be easily brushed aside, but a matter of public policy as well as a time-honored principle of procedural law.