Unlike enlisted personnel, they do not swear to obey the orders of the president of the United States.
The Cardinals were also required to swear an oath of fidelity to “Blessed Peter in the person of the Supreme Pontiff.”
I swear Rick Santorum grows ever more adorable with each passing week.
Old English swerian "take an oath" (class VI strong verb; past tense swor, past participle sworen), from Proto-Germanic *swarjan-, (cf. Old Saxon swerian, Old Norse sverja, Danish sverge, Old Frisian swera, Middle Dutch swaren, Old High German swerien, German schwören, Gothic swaren "to swear"), from PIE root *swer- (1) "to speak, talk, say" (cf. Old Church Slavonic svara "quarrel"). Also related to the second element in answer. The secondary sense of "use bad language" (early 15c.) developed from the notion of "invoke sacred names." Swear-word is American English colloquial from 1883. Swear off "desist as with a vow" is from 1898.