Human rights inhabit the space between humanity as it is and the kind of humanity we can and should be. First in people’s minds when thinking about rights is of course what an awful lot we are. We’re evil, frail, vulnerable and insignificant, and human rights try to do something about that: they counter our frailty when it’s overwhelmed by our tendency to cause harm. (Although they also protect us against the forces of nature, an often neglected or misunderstood aspect of human rights. It’s not just other people who can violate our rights).
Human rights serve to avoid the terrible, but they also aim to achieve the best. They take humanity as it is and try to reduce the pain and oppression we inflict on each other, but they also promise a better humanity, and not just better in the sense of less harmful. They promise to improve our thinking, to allow us to govern ourselves more justly and efficiently etc.
It’s important to stress this middle position of all thinking about human rights. Too much focus on one side of the is-ought divide inevitably results in distortions. Only considering human beings as they are will lead you to underestimate the power of rights. You’ll see evil as a permanent feature of history and you’ll tend to underestimate the power of moral uplift. Why do we need rights when people are as they are, and as they’ve always been? An exaggerated focus on people as they can and should be will likewise lead to a deflation of the power of rights, because you’ll tend to overestimate people’s ability to better themselves without the need for rights, and you’ll tend to envision a future in which rights will no longer be necessary. I doubt that there will ever be such a future.