Proof-reading is science as it is the system of acquiring objectively the knowledge of surface errors to rectify them; but proof reading is also an art that requires a nuanced understanding for appreciating fine-point distinctions. To me proofreading is the reading of a proof and a proof is to become the final version as it must actually be seen; and a piece of writing is to be polished to a high standard so that everything is written as it should be written. I never taught proof-reading in universities only as a science and my this understanding of proof-reading reflected in my long career of journalism.