The Declaration of Independence incorporates many Enlightenment ideas and the numerous contradictions they generated. The most obvious of these would be the notion of human rights, that each and every human being has been endowed with certain inalienable rights, simply by virtue of the fact that they are human. And that furthermore, those rights must be protected by a system of government constructed for just such a purpose:
[A]ll men are created equal.
These are arguably the most famous—and the most controversial—words in the entire document. Even at the time they were written, there were those among the Founding Fathers who felt distinctly uncomfortable with the huge chasm between the promise of equal rights and their realization in American society. If all men were created equally, then what about the slaves? Weren't they men too? Weren't they endowed by God with inalienable rights? And then there was the important question of what rights, if any, women were supposed to have.
The fundamental contradiction at the heart of the Declaration of Independence is a contradiction at the heart of the Enlightenment itself. Despite its promotion of universal values, this great intellectual movement was unable to achieve true universality on account of the unacknowledged assumptions of race, class, and gender of its leading thinkers, assumptions that are readily on display in the Declaration of Independence.