Some historians contend that the familiar provision of Magna Carta could not have meant trial by a jury of twelve and a unanimous verdict, because such a jury, according to our present knowledge, did not exist until the second half of the fourteenth century. But it is quite immaterial whether the exact form of our jury-trial existed in England in 1215, or when the Great Charter was subsequently reissued or confirmed, provided that the foundations of the system had then been laid. It is sufficient for us that the antecedents of the modern jury system in all its three forms of grand jury, criminal jury and civil jury existed at the time of Magna Carta and were preserved by it. As the jury system developed, with the changes inevitably attending all such institutions of legal procedure and machinery, the form for the time being, whatever its exact nature, became "the lawful judgment of his peers" within the intent and meaning of the Great Charter. In any event, the latest confirmations of that instrument occurred at a time when the jury system as now in force was being firmly established. It is, therefore, easy to understand how the provision "the lawful judgment of his peers" in the course of time came to be regarded as intended to guarantee the common-law jury of twelve with unanimity in verdict. Thus many, if not most, of our constitutional provisions now apply to conditions not at all contemplated by their framers although clearly within the principle enunciated and the spirit of the language used. Much of the efficacy of our federal and state bills of rights, or of any similar provisions which this Convention may embody in the new constitution, would be practically nullified if the language used were to be interpreted as being limited to the particular conditions existing when they were adopted. It is the spirit and the expanding principles of constitutional provisions which should always control. The letter killeth. A charter of liberties, a bill of rights, or a constitution is not an ephemeral enactment designed to meet only the conditions existing at the time of its adoption. It embodies and perpetuates permanent principles. It is designed to endure "forever," in the language of Magna Carta, and "to approach immortality as nearly as human institutions can approach it," in the lofty phrase of Marshall, the great Chief Justice of the United States. Under any other rule of interpretation, Magna Carta would have become antiquated long before the discovery of America.