"In Science the paramount appeal is to the Intellect-its purpose being instruction; in Art, the paramount appeal is to the Emotions-its purpose being pleasure."

Next Quote

This skipping is another important point. It should be done whenever a proof seems too hard or whenever a theorem or a whole paragraph does not appeal to the reader. In most cases he will be able to go on and later he may return to the parts which he skipped.

— Emil Artin