The traditional focuses of sociology include social stratification, social class, social mobility, religion, secularization, law, sexuality and deviance.
These were called calceus mulleus, and the name may have been shortened to mules by English speakers. Hence the primary difference between mules and clogs in early days was that clogs were likely to be worn by working people, and mules were fancier and favored by the aristocracy.
Mule (smuggling) For other uses, see mule (disambiguation). A mule or courier is someone who smuggles contraband across a border (as opposed to sending by mail, etc.) for a smuggling organization. The organizers employ mules to reduce the risk of getting caught themselves.