It is usually thought that Aristotle\u27s understanding of the soul sees it has having four distinct parts, cumulatively arranged, resulting in a kind of scala or ladder: all living things have the nutritive and reproductive soul; animals have, in addition, the sensitive soul, and most of them also the locomotive soul; only humans have all these plus the intellective soul. This ladder-like picture emerges from his theoretical work de Anima. In his more empirical studies, though, the discreteness of these levels is softened, and the image is more that of a clivus or slope, rather than a scala or ladder of nature
