The central ideas that are prevalent in both Common Sense and Washington's Farewell Address are that the<em> citizens</em> of America should be united
According to Common Sense and Washington's Farewell Address, the people in the country were urged to stay clear of permanent alliances with the foreign world.
The dangers of<em> political parties</em> were recognized and the political party was were warned not to engage in any trouble that can weaken the nation.
In conclusion, the central idea is simply about how the country can be united.