His purpose was to explain how the king wronged the people and why they should be independent. He did it by providing grievances of the king so that people can understand what is wrong and why, and he also used philosophical thoughts that were advanced for that time to explain why a republic is better than a monarchy. This was inspired by philosophers like Rousseau and Locke, and he used these to present a case not only why they should separate themselves, but also why it is the only logical and reasonable thing to do.
