The purpose of this study was to describe and classify the stages of contemplative mystical development in the major world religions. To accomplish this task, a sample of five major world religions was chosen from the total population. From each religion, a contemplative author who was regarded as an authority by the members of that religion was chosen. The major work of each author was described in order to make explicit his/her conceptualization of the stages of contemplative development. These conceptualizations were then compared together, resulting in two models of contemplative development. The first model was composed of those stages where there was agreement between four of the five authors. This model described the necessary and sufficient conditions of contemplative development and had five stages. The second model was composed of those stages where there was agreement between three of the five authors, and was postulated to address the information loss of the first model. This expanded model had thirteen stages. The implications of this taxonomy for the scientific study of religion were then explored.