We see the problem in logic presented at the end of this poem: the poet boldly dares everyone else to prove his idea of love wrong, saying that if it’s false, then he’ll never have written a word. The problem is, he puts this challenge in writing. Clearly we can’t possibly deny that he wrote anything, since the poem is right there on the page to prove it, and always will be. Confusing, we know…and also very clever. He’s basically ensuring that nobody can actually step up to the plate and challenge him. By using his own body of work as proof here, the poet makes it impossible for naysayers to claim that he’s wrong about love. This also does an interesting thing for poetry itself; by wagering his poems in this challenge, the poet also implies that literature is just as immortal and just as important as love.
Poetry is valued just as highly as love in the last two lines of the poem.