As an aesthete, Walter Pater would contend that literature, like Art, should be for the sake of literature, itself. Hence, Pater welcomes literature as a conduit of beauty, much like Art. The difference consists in that, to Pater, literature is the medium through which Art becomes illustrated, within a specific social context. This means that, although Pater treats literature as another form of Art, he does bestow upon it the social function of compiling the thoughts and philosophies that define an era, much like the Greeks did in their time. There is also a difference in that realism and aesthetics must come together in literature. This is because literature should replicate the principle of Art imitating Nature, drawing from it all its beauty.
Concisely, literature does serve an instrumental social function: that of producing beauty, through words and imagery, that comprises the sentiment of a generation, or of a specific group. Pater supports this with his views on the development of poetry in France and Italy, and how the form and content of such poetry created a collective image of beautiful outcomes.
In his theory of the Renaissance, Pater speaks about the integration of all forms of Art into poetry as a sample of the thoughts, emotions, and mentality of the people. To this, he adds
In that poetry, earthly passion, with its intimacy, its freedom, its variety–the liberty of the heart–makes itself felt; and the name of Abelard, the great scholar and the great lover, connects the expression of this liberty of heart with the free play of human intelligence around all subjects presented to it, with the liberty of the intellect, as that age understood it.
On a different note, we can conclude that Pater gives yet another value to literature: that of indoctrinating (not educating, nor moralizing) ignorant masses on the philosophies of the ancient Greeks. This particular value we see greatly expanded in the writings of Oscar Wilde, a litterateur and his most important student.
In The Picture of Dorian Gray, a novel almost entirely influenced by Pater's philosophies, we find a combination of realism (Romanticism) and aesthetics in the use of exotic words and imagery. We also see his influence in the themes that Wilde treats (Hedonism, experimentation, and a subtle type of homo-eroticism), and in the way in which the book does not aim to produce a piece of moral work, but instead "something with a quality of beauty", as Wilde himself expressed during his Gross Indecency trials (1895), as he came in defense of his book.
Concisely, the paradigms of aesthetics, Greek indoctrination, beauty, and realism are part of Pater's opinion of literature as a conduit of beauty through words. Only this time, he would spread this beauty to a society in dire need of becoming re-educated in the Greek and aesthetic styles found in the Renaissance. This is the dreadful Victorian society which both Pater and his student, Wilde, felt desperately responsible to "convert".