This paper will explore the role of psychedelics within Big History in the context of evolutionary brain development. Looking at theories from evolutionary anthropology, neuroscience, and moral philosophy, the first part describes the birth and evolution of religion. The second part will look at recent empirical data from the neurosciences on the effect psychedelics have on the brain, along with speculations on the role of psychedelics in our hominoid evolutionary history. Specifically, the capacity for phenomenologically rich, conscious, subjective experiences that are incredibly vivid and real. This imaginative capacity for transcendence and disembodiment would allow for new forms of abstract, absolute, and perfect concepts to be realized.

Furthermore, the influence of epigenetic neurogenesis could have allowed our brain to expand and function the way it now does, with its complex neural structures that allow for conceptualization, visualization, association, and categorization, which would allow for more advanced structures of vocalized noises, such as syntax and eventually meaning. The third part will look at classical moral realism within the framework of the theories laid out in the first two parts and propose a position of embodied moral realism. That is, accepting that moral facts are like natural facts, but rejecting that moral facts are mind-independent or disembodied.