This article continues the construction of a dualistic interactionist theory of the near-death experience (NDE), the theory of essence, which was begun in two previous articles (Arnette, 1992, 1995). The present work represents an extension of the theory to the microscopic level of analysis, in order to specify in detail the mechanism of essence-brain interaction and to address some general and specific objections to interactionism and the theory of essence. In the theory construction process, a second issue is addressed: that of the apparent multiplicity of causes of NDEs or NDE-like experiences. I show that this multiplicity is simply a manifestation of the mode of essence-brain interaction and is accurately predicted by the theory.