The use of metaphors can greatly influence the effectiveness of an author's message, when used correctly. John Donne turns this tool into an art form in his poetry as he weaves absurd relationships between two or more seemingly unrelated ideas. Not only does this make his poems much more entertaining but it also helps to express his ideas in a very vivid manner. This helps the reader to relate to and more fully understand the complexity of the feelings being expressed.
One good example of Donne's use of absurd metaphors is in the poem entitled "The Flea". In this poem the flea is used in a humorous matter in order to down play the female's reluctance to give up her virginity. In lines 1 and 2 Donne begins by telling the female how unimportant her virginity is. In order to back this up he continues by presenting the first, and main, metaphor that the flea is sex between these two lovers. At first this seems absurd but it is made to work by Donne laying out plainly how he came to the conclusion that the flea is the same as sex. In line 4 the point is made that when the flea bit the male and the female the bodily fluids of the two were immediately mixed within the flea. Donne goes on to tie in how this proves that sex between the two will not be a big deal by saying, "Thou know'st that this cannot be said a sin, or shame, or loss of maidenhead" (lines 5-6). He also points out that the flea did this without the permission of either of them and did nothing to court them.
Donne's use of metaphors continues in the second stanza as the female is about to kill the flea. The death of the flea is portrayed as a tragic event, compared to killing three people at once. It can be argued that this is a reference to the holy trinity, which makes the metaphor even more absurd and also makes it that much worse to kill this flea. In lines 12-13 three more metaphors are stated as the flea is compared to "you and I", "our marriage bed", and "marriage temple".