Can anything new really be said?

Even a brief examination of the history of literature, poetry and playwriting reveals that much of humankind's essence has already been explored in a myriad forms. We, as modern writers, are trying to find new things to say about emotions, beliefs, states of mind, and ideas that have been with us for millennia. Can anything new be said, or is everything just a reformulation of old things? Has writing exhausted its potential for innovation?

All said, does novelty even matter? It could be that there is "nothing new under the sun" in terms of literary explorations of emotions, thoughts and human experiences. However, is it more important that something new actually be said or that an artist tries to do so? Why? What makes either attempt successful or unsuccessful?