Mercuzio is a foil for Romeo because he makes a lot of jokes and punksters about love, while Romeo acts seriously. Mercuzio targets in his ridicule not in love as such, not in the great human feeling, so highly valued by the people of the Renaissance. He mocks is over the conventions, which his friend is trying to decorate his hobby. If Romeo, speaking of his love, compares it with the mist, then Mercuzio likens the feelings in which Romeo is located, the swamp where Romeo mired under to his ears and whence he should be pulled out. Mercutio mocks the love that Romeo thinks of as romantic and necessary.