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 (plural mules) A generally sterile male or female hybrid offspring of a male donkey and a female horse. A generally sterile hybrid offspring of any two species of animals. A hybrid plant. A stubborn person. A person paid to smuggle drugs.