Thomas Paine (1737—1809) was an early American political theorist most active during the late eighteenth-century. His early activity in support of the American Revolution and his later work in France during the French Revolution demonstrates his extreme skepticism about the efficacy and justness of monarchy. Moreover, his writings betray an even more pointed anti-royalist sentiment and highlight his low opinion of the King of Britain specifically and of monarchy generally.
In his 1775 pamphlet Common Sense, Paine sets out his thesis that monarchy is the cause of international war, observing
In the early ages of the world, according to the scripture chronology, there were no kings; the consequence of which was there were no wars; it is the pride of kings which throw mankind into confusion.
In his 1791 book The Rights of Man, meanwhile, Paine argues that monarchy is the opposite of a meritocracy because it allows into positions of high power anyone regardless of their capacity or intellect for the job:
Kings succeed each other, not as rationals, but as animals. It signifies not what their mental or moral characters are.