Gothic architecture superseded the Romanesque style by combining flying buttresses, gothic (or pointed) arches and ribbed vaults. It was influenced by the spiritual background of the time, being religious in essence: thin horizontal lines and grates made the building strive towards the sky. Architecture was made to appear light and weightless, as opposed to the dark and bulky forms of the previous Romanesque style. Saint Augustine of Hippo taught that light was an expression of God. Architectural techniques were adapted and developed to build churches that reflected this teaching. Colorful glass windows enhanced the spirit of lightness. As color was much rarer at medieval times than today, it can be assumed that these virtuoso works of art had an awe-inspiring impact on the common man from the street. High-rising intricate ribbed, and later fan vaultings demonstrated movement toward heaven. Veneration of God was also expressed by the relatively large size of these buildings. A gothic cathedral therefore not only invited the visitors to elevate themselves spiritually, it was also meant to demonstrate the greatness of God. The floor plan of a gothic cathedral corresponded to the rules of scholasticism: According to Erwin Panofsky's Gothic Architecture and Scholasticism, the plan was divided into sections and uniform subsections. These characteristics are exhibited by the most famous sacral building of the time: Notre Dame de Paris.