To stop short of simply disregarding the speculation of other parties, John Locke is not the only man that has been cited as the primary voice of reason that guided Thomas Jefferson as he wrote the Declaration of Independence for the blossoming United States. There is a relatively well established alternate theory that it is actually Leibniz who is behind that voice of reason, and that it is ridiculous to think that Locke would have been Jeffersonâ€™s intellectual fuel because Locke was, in fact, deeply loyal to England. These different views seem to be settled in their places well, each on its own side of the thin party-line of modern politics.
First of all, Lockeâ€™s support would not have been necessary in order for the American colonies to cite his work in making their case against the Crown. (In fact, in a way, Lockeâ€™s disapproval of the American stance could have served the Declaration well, provided that Lockeâ€™s principles and ideas held with a strong footing before the masses and their thoughts.) Secondly, Leibniz was not particularly as relevant to Thomas Jeffersonâ€™s purpose as Locke was, and that makes citing Leibniz as Jeffersonâ€™s inspiration simply inaccurate.
Having put that aside with enough certainty, several specific chapters in Lockeâ€™s Two Treatises can be referenced as direct influences on the Declaration itself, namely chapters three â€˜Of the State of Warâ€™, five â€˜Of Propertyâ€™, eighteen â€˜Of Tyrannyâ€™, and nineteen â€˜Of the Dissolution of Governmentâ€™.
The short chapter defining and explaining what Locke calls the â€˜state of warâ€™ is a testament to Jeffersonâ€™s and the coloniesâ€™ understanding of the stakes that were drawn as King George received their declaration. To put the chapter into a nutshell, an educated person with an understanding of societyâ€™s function does not enter oneself into a â€˜state of warâ€™ with another unless he deems it prudent and a necessary course of action.