Romantic literature in all its many forms was primarily concerned with expressing subjective emotion. This represented a radical departure from the previously dominant Neo-classicism aesthetic, which held that works of art, including literature, should reflect timeless, universal truths. In other words, art should reflect reality, what was "out there" in the world, instead of giving expression to the individual artist's soul.
For the most part, Romantic writers sought to rediscover the truth-telling power of the emotions, a power that had been almost completely lost since the age of the Enlightenment, when reason had been privileged over the emotions. In getting in touch with their emotions, the Romantics believed that they would rediscover what it is that unites human beings with Nature. Modern science had separated man from nature, turning the latter into an object of study and exploitation. But man's emotional life could give him a completely different perspective, allowing him to feel his kinship with the world around him, to feel within his soul the essential oneness that unites every living thing in a comprehensive whole.