The value-oriented understanding of fundamental rights and constitutional law by the Federal Constitutional Court remains precarious in its rationality and legitimacy as a prae judicial creation. Thilo Rensmann reveals a reserve of rationality by incorporating the cross-border context, which has not yet been sufficiently appreciated. The main thesis of his investigation is that the Basic Law and the value-order jurisprudence of the Federal Constitutional Court have been embedded from the very beginning in the context of the emerging transnational human rights constitutionalism after World War II, and therefore can only be fully understood in this context. He demonstrates the genetic connection between the fundamental rights of the Basic Law and the human rights value system of the international community, as articulated in the Universal Declaration of Human Rights.