An unconstitutional constitutional amendment is a concept in judicial review based on the idea that even a properly passed and properly ratified constitutional amendment, specifically one that is not explicitly prohibited by a constitution's text, can nevertheless be unconstitutional on substantive (as opposed to procedural) grounds—such as due to this amendment conflicting with some constitutional or even extra-constitutional norm, value, and/or principle.[1][2][3] As Israeli legal academic Yaniv Roznai's 2017 book Unconstitutional Constitutional Amendments: The Limits of Amendment Powers demonstrates, the unconstitutional constitutional amendment doctrine has been adopted by various courts and legal scholars in various countries throughout history.[1] While this doctrine has generally applied specifically to constitutional amendments, there have been moves and proposals to also apply this doctrine to original parts of a constitution.