The reason is plain. Back in the ages, there was a time when scientific men “_knew_” that the earth was flat. Because _they_ “knew” it, the rest of men assumed that it was so. And, because _they_ “knew” it, it was most difficult to convince _them_ that their “knowledge” was _false_ “knowledge.” In a similar way, our statesmen and constitutional thinkers came to the year 1917 with the “knowledge” that legislatures in America, if enough of them combined, had exactly the omnipotence over the individual freedom of the American which had been denied to the British Parliament by the early Americans. Naturally, it is difficult for _them_ to understand that their “knowledge” is _false_ “knowledge.” For us who have no false knowledge to overcome, it is comparatively simple to grasp what those other plain Americans of 1787 and 1788 meant to accomplish and did accomplish. Why should it not be simple for us? With those other plain Americans, we have just been through their strenuous years which immediately preceded their greatest days of 1787 and 1788. They were a simple people as are we average Americans of this generation. From living with them through those earlier days, we have come to know their dominant purpose. They sought to secure to themselves and to their posterity the greatest measure of protected enjoyment of human life, liberty and happiness against interference from outside America and against usurpation of power by any governments in America. Certainly, it ought not to be difficult for us to grasp accurately and quickly what they meant to do and what they did do in their last and greatest achievement in the quest of that protected enjoyment of human freedom. But, with all our happy predisposition accurately to understand the meaning of the facts in 1787 and 1788, that understanding cannot come until we know the facts themselves. Let us, therefore, live through those years with those other plain Americans of whom we _are_ the posterity. Only then can we understand their legacy of secured liberty to us _and keep it against usurpation by those who do not understand_.