This unit in the No. 86 video curriculum explores some key ideas that undergirded the writing of the Constitution: natural rights, separation of powers, mixed regime theory, federalism. These ideas came from varied sources: the British Constitutional experience, English and Scottish Enlightenment scholars, the French philosopher Montesquieu, and others. The Constitution is a complex document, one that was ratified only after intense debate. Originalism explores that complexity so that we can better understand the document. But do all Originalists agree on how and why to approach this study of the Constitution?