Vodou holds that Bondye created humanity in his image, fashioning humans out of water and clay. It teaches the existence of a spirit or soul, the "espri", which is divided in two parts. One of these is the "ti bònanj" or ' ("little good angel"), and it is understood as the conscience that allows an individual to engage in self-reflection and self-criticism. The other part is the "gwo bònanje" or ' ("big good angel") and this constitutes the psyche, source of memory, intelligence, and personhood. These are both believed to reside within an individual's head. Vodouists believe that the gwo bònanje can leave the head and go travelling while a person is sleeping.