Volcano of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes. There is no consensus among volcanologists on how to define an "active" volcano. The lifespan of a volcano can vary from months to several million years, making such a distinction sometimes
Dormant Commerce Clause Treasury of MD. v. Wynne", the Court addressed Maryland's unusual practice of taxing personal income earned in Maryland, and taxing personal income of its citizens earned outside Maryland, "without" any tax credit for income tax paid to other states. The Court held this sort of double-taxation to be a violation of the dormant Commerce Clause. The Court faulted Justice Antonin Scalia's criticism of the dormant Commerce Clause doctrine by saying that he failed to "explain why, under his interpretation of the Constitution, the Import-Export Clause would not lead to the same result that we reach under the dormant Commerce Clause".