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.
Mules have been said to have the body of the horse with extremities of a donkey, whereas hinnies have the body of a donkey and the extremities of a horse. Because a donkey mare is smaller than most horses, hinnies are generally smaller than mules.