Enlightenment's emphasis on order and reason was the main characteristic of Neoclassicism which was also called "the age of reason" since all had to be explained by means of the reason.
As a reaction against Neoclassicism, Romanticism CELEBRATED EMOTIONS, it went for imagination and the authors wanted to do away with traditional forms. As an example of imagination, we could mention that in Romanticism it was common to find characters coming back from death (Frankenstein).