In america, the movement known as romanticism took two forms: bright romanticism, or transcendentalism, and dark romanticism. what do transcendentalism and dark romanticism have in common?

Their philosophies are similar. Both movements were born as a reaction to strict traditions, laws and religious rules. They both opposed Calvinism. They both thought that an individual, as well as nature are important. No rules should be obeyed - both movements thought that. 

To persuade someone not to take a particular course of action