Final answer:
Jefferson positioned the idea of equality and the right to alter or abolish unjust governments based on Enlightenment principles of natural rights and the philosophies of John Locke. He and other founders did not tackle slavery head-on in their founding documents due to limited abolitionist support of their time.
Step-by-step explanation:
Thomas Jefferson placed the phrases “all men are created equal” and the right of the people to “alter and to abolish” government prominently in the Declaration of Independence based on the Enlightenment ideals of John Locke and the concept of natural rights. Generations of Americans and others have grappled with Jefferson's ownership of enslaved individuals alongside these universal claims to equality. While he recognized the contradiction and privately condemned slavery, he and the other founders did not definitively address the issue. The notion that governments are instituted to secure natural rights and derive their power from the consent of the governed implies that it is not hypocritical for a society that practices slavery to also fight for its own freedom. Furthermore, the political support for abolition was not widespread at the time, so such statements were intended to lay a foundation for the future, rather than address every existing societal flaw.