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.
The Mule is a cross between a donkey stallion (called a jack) and a horse mare. Hinnies are just the opposite-a stallion horse crossed to a donkey jennet. For all purposes, hinnies and mules are classified and shown together under the general term Mule.