beneath words

The old man answered the young man, 'Something that sounds absurd - because it's unfamiliar - may give the lie to what's accepted. Associations hidden by common usage of language can be discovered.'

The old man took pencil and paper and wrote, 'a cause from a cause that comes from an effect.' After writing a list of prepositions beneath the words 'from', he instructed the young man, 'Now make substitutions for each 'from' in any combination. My point will be evident.'