"Substantive Due Process" is the fundamental constitutional legal theory upon which the Griswold/Roe/Casey privacy right is based. The doctrine of Substantive Due Process holds that the Due Process Clause not only requires "due process," that is, basic procedural rights, but that it also protects basic substantive rights. "Substantive" rights are those general rights that reserve to the individual the power to possess or to do certain things, despite the government’s desire to the contrary. These are rights like freedom of speech and religion. "Procedural" rights are special rights that, instead, dictate how the government can lawfully go about taking away a person’s freedom or property or life, when the law otherwise gives them the power to do so.