 Gisbert Rinschede distinguishes these by duration, by group size, and by social structure.Juli Gevorgian proposes two categories that differ in their motivation, namely "pilgrimage tourism" for spiritual reasons or to participate in religious rites, and "church tourism" to view monuments such as cathedrals.The Christian priest Frank Fahey writes that a pilgrim is "always in danger of becoming a tourist", and vice versa since travel always in his view upsets the fixed order of life at home, and identifies eight differences between the two