African art creates one of the most diverse legacies in the world. Although many casual observers generally generalize "traditional" African art, the continent is made up of a great diversity of people, each with a particular visual culture (Boundless). Most African sculptures were historically made of wood and other organic materials that did not survive until at most a few centuries ago. Ancient pottery figures are found in a number of regions, usually in North Africa. Masks are important elements in the art of many peoples, just like human figures, often very stylized. The human figure has always been the key subject of most African art, and this importance has even impacted some European traditions. For example, in the 15th century, Portugal traded with the Sapi, a culture close to the Ivory Coast in West Africa, who created decorative ivory salt shakers, hybrids of African and European models. Additionally, the African art of dance was practiced in many spiritual ceremonies, celebrations and performances. It is wrong to believe that the first philosophers were the Greeks, but in reality they were the Africans. The African continent is divided into two major divisions, North Africa and Sub-Saharan Africa, with very different political and cultural philosophies. North African philosophers have made important contributions to Greek, Jewish, Islamic and Christian history.