Throughout the novel, Don Quixote and Sancho Panza serve as foils for each other despite their close companionship. The stark contrast in their character is evident in a famous episode in the novel in which Don Quixote mistakes windmills for giants:
‘What giants?’ said Sancho Panza.
‘Those giants that you can see over there,’ replied his master, ‘with long arms: there are giants with arms almost six miles long.’
‘Look you here,’ Sancho retorted, ‘those over there aren’t giants, they’re windmills, and what look to you like arms are sails [...]'
‘It is perfectly clear,’ replied Don Quixote, ‘that you are but a raw novice in this matter of adventures. They are giants; and if you are frightened, you can take yourself away and say your prayers while I engage them in fierce and arduous combat.’