As reflected in La scienza nuova (1725; The new science), Vico sees language as a social construction intimately involved with cognitive development and epistemology. Because society has changed—moving from an original theological stage, through a heroic epoch, to a present-day civilized, humanistic order—so, too, have language and human nature altered. Articulating ideas similar to those espoused by later, Romantic philosophers, such as Jean Jacques Rousseau (1712–1778) and Johann Gottfried von Herder (1744–1803), Vico postulates that, during the theological epoch (which has its analog in individual cognitive development), humans shared a primitive, metaphorically rich language, which was later complicated and variegated through cultural pressures and the advance of rational thinking. Rather than the opposite or absence of thought, figurative language demonstrates an elemental mode of thinking that Vico calls "poetic logic."
Samuel Taylor Coleridge (1772–1834) serves as a particularly influential specimen of Romantic thinking about metaphor. Neoplatonic in inclination and influenced by Vico, Rousseau, and the German Romantics, Coleridge famously distinguishes between imagination and what to him is the inferior mode of fancy, thereby clarifying his age's impatience with the limits of empirical knowledge. To Coleridge, imagination is a creative, connective power that unites nature and the poet, whose genius is realized through "organic," original form rather than "mechanic," derivative form. Coleridge defines poetry—and thus the exercise of its modes, such as metaphor—as a self-expressive activity whose object (pleasure) is opposed to that of science (truth).
Although Coleridge maintains that poetry enables a view of nature superior to that obtained through scientific inquiry, his system effectively treats poetry and science as complementary opposites: each (paradoxically) capable of discovering, through its specific symbolic activity, aspects of the reality that simultaneously undergirds and lies beyond symbols. Coleridge's Neoplatonic view of nature and its potential accessibility through human inquiry were not, however, shared by all Romantic thinkers. In particular, Friedrich Nietzsche (1844–1900) unequivocally states that human beings are "indifferent" and even hostile to "pure knowledge," to the "thing in itself." More important, Nietzsche denies that language—and by way of extension, any symbolic activity—is capable of revealing any meaning beyond that which it constructs. From this anti-essentialist perspective, the truths obtained through language are "illusions," members of a "worn out" "army of metaphors." Nietzsche is not, however, recycling a Ramist or Baconian position: To him a metaphor-free language is as impossible as a value-free science. In Nietzsche's opinion, metaphor and reality are so entwined as to be synonymous.