Stoppani was important as a popularizer of science. His most popular work, "Il Bel Paese, conversazioni sulle bellezze naturali la geologia e la geologia e la geografia fisica d'Italia" (1876) ("The Beautiful country, conversation on the natural beauty of geology and the physical geography of Italy"), after which Bel Paese cheese was named by Egidio Galbani (the wrapper for the cheese included a portrait of Stoppani). It presents, by means of 32 didactic, scientific conversations supposedly in front of a fireplace, ideas and concepts from the natural sciences, in language accessible to the average 19th-century reader. It was so popular that it went into 120 editions by 1920 and was a textbook in schools. It deals especially with geological curiosities and the beauty of the Italian landscape. He commented on Italians who "know almost nothing about the natural beauty of our country; yet take delight when someone calls it a garden" and that the English fall in love with just one thing and devote their energies, emotions, and life to arrive dead or alive at the summit of mountains. His introduction to natural history declared that ""man should never disappear from nature, nor should nature disappear from man"". Stoppani, like many other clergyman naturalists of the period, was a supporter of the "concordismo", a school of thought that sought to find concordance between the teachings of the bible and evidence from geology. He promoted the idea that Catholics needed to learn science and that the bible was to be interpreted rather than taken literally. He was also an important figure in "Catholic Alpinism", a movement that sought to use mountains to tell God's glory. Stoppani was however a critic of the ideas of evolution that Darwin's publication had brought into Europe.