The error in the reasoning of this excerpt is the assumption that the government can justly create any law that it wants, short of taking away a person's bare necessities. By this logic, slavery is fine as long as the slave has food, water, and shelter. The slave has no right to complain as long as he's better off than he would be in the most primitive state of nature.

The declaration of independence expresses a better view: we are endowed with liberty by our Creator and it is the role of government to protect that liberty. Under this view, government's actions can be judged.