Howard Dietz disease. Howard Dietz Howard Dietz (September 8, 1896 – July 30, 1983) was an American publicist, lyricist, and librettist. Dietz was born in New York City. He attended Columbia College and then studied journalism at Columbia University. He also served as publicist/director of advertising for Goldwyn Pictures and later MGM and is often credited with creating Leo the Lion, its lion mascot, and choosing their slogan "Ars Gratia Artis". In 1942, he was made MGM's Vice President in Charge of Publicity. He held that position until his retirement in 1957. He began a long association with composer Arthur Schwartz when
Ars Magna (Gerolamo Cardano) is square roots of negative numbers appear naturally in this context. However, "q"/4 + "p"/27 never happens to be negative in the specific cases in which Cardano applies the formula. Ars Magna (Gerolamo Cardano) The Ars Magna ("The Great Art") is an important Latin-language book on algebra written by Gerolamo Cardano. It was first published in 1545 under the title "Artis Magnæ, Sive de Regulis Algebraicis Liber Unus" ("Book number one about The Great Art, or The Rules of Algebra"). There was a second edition in Cardano's lifetime, published in 1570. It is considered one of the three greatest scientific