“Arguments for preservation based on the beauty of wilderness are sometimes treated as if they were of little weight because they are "merely aesthetic". That is a mistake. We go to great lengths to preserve the artistic treasures of earlier human civilisations. It is difficult to imagine any economic gain that we would be prepared to accept as adequate compensation for, for instance, the destruction of the paintings in the Louvre. How should we compare the aesthetic value of wilderness with that of the paintings in the Louvre? Here, perhaps, judgment does become inescapably subjective; so I shall report my own experiences. I have looked at the paintings in the Louvre, and in many of the other great galleries of Europe and the United States. I think I have a reasonable sense of appreciation of the fine arts; yet I have not had, in any museum, experiences that have filled my aesthetic senses in the way that they are filled when I walk in a natural setting and pause to survey the view from a rocky peak overlooking a forested valley, or by a stream tumbling over moss-covered boulders set amongst tall tree-ferns, growing in the shade of the forest canopy, I do not think I am alone in this; for many people, wilderness is the source of the greatest feelings of aesthetic appreciation, rising to an almost mystical intensity.”

Source: Practical Ethics