Final answer:
Jean-Jacques Rousseau's philosophy aligns with the idea that sovereignty resides in the nation, as he emphasized the general will and sovereignty of the people rather than divine right or individual authority.
Step-by-step explanation:
The Enlightenment philosopher who would agree with the idea that "The principle of sovereignty resides essentially in the nation and no authority should be exercised unless it comes directly from the nation" is Jean-Jacques Rousseau. Rousseau's philosophy emphasized the concept of the general will, which holds that the legitimacy of state authority derives from the collective will of the people.
His belief was that the government should represent the general will of its citizens, ensuring that all exercised their sovereignty through the nation directly, not through monarchs or individual rulers claiming divine right or other forms of legitimacy.