What were the "self-evident truths" from the Declaration of Independence?
The truths the writers of the Declaration of Independence held to be "self-evident" are outlined explicitly in the document on a point-by-point basis. The first is that all men are created equal, an overt dismissal of ideas such as aristocracy and other social structures which accorded men greater or lesser status because of the circumstances of their birth. Next, men are afforded certain rights by God that are "unalienable" (cannot be taken from them): they have the right to "life, liberty, and the pursuit of happiness."
The next stipulation is that it is the primary purpose of governments to help men pursue these rights and that governments derive their validity from the consent of those they rule. Finally, the document stipulates that if a government does not have the consent of those it governs or if it is not helping its people secure their "unalienable rights," then the people are absolutely within their rights to dismantle the government, as it has proven itself invalid and unfit to govern.
There are four major parts to the self-evident truths spoken of in the Declaration.
First, there is the idea that all "men" are created free and equal. This was meant to show that monarchy and hierarchy did not make sense.
Second, there was the idea that all men were given certain "unalienable rights" by God. In the Declaration, these rights are enumerated as the rights to "Life, Liberty and the pursuit of Happiness."
Third, there was the idea that government had to rule with the consent of the people.
Finally, there was the idea that any government that did not rule by the consent of the governed and protect the rights of the people was liable to be overthrown by rebellion.
These ideas were taken directly from the writings of Enlightenment thinkers like John Locke. By using these ideas that were already quite well-known in Europe, the colonists were able to justify their rebellion against England.