Pliny, Letter 10.34

1The idea has occurred to you, following the example of many places, that a guild of workmen could be set up at Nicomedia. 1But let us remember that that province, and especially those cities, have been troubled by factions of this kind. 1Whatever name we give, and for whatever reason, to those who have been brought together for a common purpose, they will become political clubs, and quickly. 2It is better, therefore, that the things which can help in checking fires be procured, and that owners of property be urged to put them out themselves and, if the situation demands, to make use of the crowd that runs together for this purpose.