A paradox is a statement that contradicts itself and still seems true somehow. Fancy that. Everyday examples include, "Nobody goes to the restaurant because it's too crowded." Or how about "This sentence is false." Or "I know that I know nothing."
Paradoxes in literature are often less about logical conundrums and more about illuminating meaning. While paradoxes may seem totally contradictory, literary paradoxes are often totally true at the same time.
It's a paradox when John Donne writes in his "Holy Sonnet 10", "Death, thou shalt die," because he's using "death" in two different senses. Death can't die, can it? Well, strictly speaking, it can't, but the speaker is trying to show that mortality is, in a weird way, mortal itself. Is your mind blown? Good, then the paradox did its job.
Literature is full of ambiguity, contradictions, and even confusion. So when Shmoop talks paradoxes, we like to remember the wise words of our buddy Walt Whitman:
Now imagine a paradox speaking those words, and you'll catch our drift.