 Some modern teachers have interpreted the doctrine of the six realms as a psychological process unfolding in this one life: the realms are understood as the different ways we understand the world when under the influence of the reactive emotions of anger, greed, stupidity, desire, competitiveness, and pride. (See, e.g., McLeod 2002, 146–51.) But historically, most Buddhists have taken this system literally, as a cosmological account of how the world works and what happens when we die. Therefore, to avoid the actions most likely to drive them into the lower realms, many Buddhists have undertaken to obey rules of moral discipline.