The American spiritual writer and philosopher uses a concept called the "Great Nest of Being" which is similar to the great chain of being, and which he claims to belong to a culture-independent "" traceable across 3000 years of mystical and esoteric writings. Wilber's system corresponds with other concepts of .
In the 1977 book , British philosopher and economist wrote that fundamental gaps exist between the existence of minerals, plants, animals and humans, where each of the four classes of existence is marked by a level of existence not shared by that below. Clearly influenced by the great chain of being, but lacking the angels and God, he called his hierarchy the "levels of being". In the book, he claims that science has generally avoided seriously discussing these discontinuities, because they present such difficulties for strictly materialistic science, and they largely remain mysteries.
The real distinction between essence and existence, and that between form and matter, which served for so long as the basis of metaphysics, Hobbes identifies as "the Error of Separated Essences." The words "Is, or Bee, or Are, and the like" add no meaning to an argument nor do derived words such as "Entity, Essence, Essentially, Essentiality", which "are the names of nothing" but are mere "Signes" connecting "one name or attribute to another: as when we say, , we mean not that the is one thing, the another, and the , or a third: but that the , and the , is the same thing; ..." Metaphysiques, Hobbes says, is "far from the possibility of being understood" and is "repugnant to natural reason."