Human dignity seems very important to us. At the same time, the concept ‘human dignity’ is extrordinarily elusive. A good way to approach the questions “What is it?” and “Why is it important?” is to raise another question first: In virtue of what do human beings have dignity? Speciesism - the idea that human beings have a particular dignity because they are humans - does not seem very convincing. A better answer says that human beings have dignity because and insofar as they are persons. I discuss several versions of this idea as well as several objections against it. The most promising line of analysis says that human beings cannot survive psychologically without a very basic form of recognition and respect by others. The idea that humans have a very special dignity is the idea that they owe each other this kind of respect. All this also suggests that human dignity is inherently social. Non-social beings do not have dignity - nor do they lack it. It is because we are social animals of a certain kind that we have dignity - not so much because we are rational animals.