The language of literature is steeped in metaphor, imagery and poetry. The literary author wants to affect the reader on an emotional level, to touch into feelings of sympathy, pity, anger, outrage, humor, etc.. in order to express themes appropriate to the time period and subject matters addressed. Irony, understatement, overstatement, paradox, and blatant contradiction are often used to accomplish these goals, to unsettle the reader, to effect change. Strongly worded and elaborate sections of imagery are often used to express ideas - consider the entire first chapter of The Scarlet Letter in which Hawthorne is reminding readers that while crime is always an element of any civilization, the goodness of human nature will rise above it. However, instead of simply saying that, he spends the chapter simply describing a prison door and a solitary rose growing by it.
The language of science is designed to catalog experience. Science wants to find order in chaos, and explanations for mysteries. As such, the scientist is going to use specific and concise language. The scientist will not attempt to beautify or humanize an object, but only to classify it as specifically as possible. A rabbit is a mammalian quadraped in the family of leporidae, as far as the scientist is concerned. However, a rabbit could be the furry companion of all energetic and wily creatures, a four-legged bringer of luck and prosperity... at least he could be when the poet gets a hold of him!
So, the language of literature is based in imagery and figurative language in order to touch into the emotional base of humanity. The language of science is based in jargon and specificity in order to catalog objects, living creatures and experience into neat, orderly, and easy to understand classifications.