Obstacles (Tib. བར་ཆད་, barché; Wyl. bar chad) on the spiritual path are often classified into outer, inner and secret categories (Tib. ཆི་ནང་གསང་བའི་བར་ཆད་, Wyl. chi nang gsang ba'i bar chad). Another way of looking at obstacles is called the four maras or four demons.