The Etymology of Licence
Licence has always been double-edged. Latin licentia meant both 'permission' and 'excessive freedom' — the liberty to act and the danger of acting without restraint. Roman writers used it approvingly for sanctioned authority and disapprovingly for moral looseness, sometimes in the same paragraph. English inherited both senses when it borrowed the word through Old French in the 14th century. The official-permission sense produced driving licences, software licences, and the Licensing Act. The excess-freedom sense produced licentious, poetic licence, and the phrase 'licence to print money'. The spelling distinction between British licence (noun) and license (verb) follows a pattern borrowed from French that also governs advice/advise and practice/practise. The c-for-nouns, s-for-verbs rule is consistent but widely misapplied, making licence one of British English's most frequently misspelled words. American English cut the knot by using license for everything. The Latin root licere ('to be allowed') also produced licit, illicit, and — through a more winding path — leisure, which originally meant 'permitted time', time when you were allowed to stop working. The connection between permission and free time runs deeper than most English speakers realise.