 Jean-Pierre de Crousaz, a professor of logic and mathematics in Lausanne, Switzerland, published his Treatise on Beauty in 1715. He does not offer original ideas on the nature of the beautiful; he takes up the old dictum that it is a mix of unity and diversity, so as to preserve order and proportion from both caprice and monotony. But he approaches it with a new awareness of the constraints and prejudices that obstruct the way: 