James Champlin Fernald,
English Synonyms and Antonyms
“ Ease of action may imply merely the possession of ample power; facility always implies practise and skill; any one can press down the keys of a typewriter with ease; only the skilled operator works the machine with facility. Readiness in the active sense includes much of the meaning of ease with the added idea of promptness or alertness. Easiness applies to the thing done, rather than to the doer. Expertness applies to the more mechanical processes of body and mind; we speak of the readiness of an orator, but of the expertness of a gymnast. Compare COMFORTABLE; DEXTERITY ”
