sentences:  He explained that he meant "moral as well as material truth".The job of the artist is to observe the reality of nature and not to invent it in a studioto render imaginatively on canvas what he has seen and understood, free of any rules of composition.For Ruskin, modern landscapists demonstrated superior understanding of the "truths" of water, air, clouds, stones, and vegetation, a profound appreciation of which Ruskin demonstrated in his own prose.