The Tree of knowledge (ToK) system is a new map of Big History that traces cosmic evolution across four different planes of existence, identified as Matter, Life, Mind and Culture that are mapped respectively by the physical, biological, psychological and social domains of science. The Tree of Knowledge (ToK) System was developed by Gregg Henriques, who is a professor and core faculty member in the Combined-Integrated Doctoral Program in Clinical and School Psychology at James Madison University. The ToK System is part of a larger Unified Theory of Knowledge that Henriques describes as a consilient scientific humanistic philosophy for the 21st Century.