We discuss the phylogenetic basis of states of consciousness, and present the central theses of monism and dualism, in which near-death experiences (NDEs) enjoy very different ontological statuses. Next, we sum marize the evolution of the genus Homo, with emphasis on neuroanatomical changes, and define brain and consciousness states. Data suggest that con sciousness states are produced by brain states. We address the problem of states of consciousness in other species because consciousness states seem to emerge from a phylogenetic continuum, and analyze problems connected with verbal reports of internal experiences. Finally, we examine NDEs as brain states/consciousness states, and conclude that we need further study of elements appearing in each NDE with their order of appearance. We dis cuss problems in the relationship between brain states and consciousness states, and conclude that science does not need a paradigm shift to deal with NDE data. Every word and every brain, And our ancient family line ... Everything must come to death.-Michelangelo Buonarotti, Sonnet, 16th century When a new phenomenon is accepted as being real, a first step in its study is its observation and classification. At this stage, specula tion about its origin and composition is normal. Sometimes this stage