"The purpose of anthropology is to understand...."
The second those words leave your lips or your pen, you have misspoken. It doesn't matter what comes after, you are wrong. Because "understanding" is always a means and never a goal. Only the most naive of positivists would suggest that we seek knowledge for the sake of knowledge. And so only they would not append a "so that" onto the end of the statement: "The purpose of anthropology is to understand X so that Y." It doesn't matter what X and Y are, the real purpose is always Y and X - "understanding" - is merely a means. But if the purpose is Y, why limit your repertoire of means to X? Why not say "the purpose of anthropology is Y, by whatever means available"? But let's step back from that and think about what the purpose of anthropology actually is, and how we can define ourselves.
The purpose of anthropology is to create a better world. I say that completely without irony or sarcasm, and it is only apparently normative. I am not saying "the purpose of anthropology should be to create a better world." I am saying that it is to create a better world. How can I say that? How can I impose my purpose upon the vast field of anthropology with all of its different practitioners, each with their own vision of a "better" world and each with a different set of values and goals?
First of all,the world does not simply exist as it is - there are no givens, and nothing just is the way it is. Rather the world is created anew in every moment by the many different entities that compose (in both senses of the term) it. Through our practices - no matter what they are - we compose the world as a massive, collaborative, and temporally and spatially continuous artscape. Even our representations of the world - paintings, photos, writings, etc. - in a very fundamental sense are the world. It's time we pay attention to that.
So if our actions compose the world (but, and this is key, not our actions alone - this is a collaborative effort), then anthropologists already are creating a world. It simply can't be helped. Thus the statement "the purpose of anthropology is to create a world" is simply obvious. But where does the "better" come in? Isn't that a normative claim? I would argue that it isn't, but I would say it's based on an assumption which I suspect is valid but can't be certain of. The assumption is that everyone is trying to make the world better by whatever vision they are guided. Of course, we all don't agree on that vision, and so what one person sees as making the world better may look like making the world worse to another. The statement only becomes normative if I define for you what "better" means. Of course I have a vision of what a better world would look like, but I can no more impose that vision on you than you would impose it on me because, as I said before, this is a collaborative effort. However, I can work with you to create a world that fits both our needs and visions as much as possible. That means that we both allow ourselves to be altered by one another equally - giving where the other gives, and pushing back where the other pushes back.
But speaking of the purpose of anthropology as creating a world is too vague to be useful. It's important to bear in mind, but not enough for us to identify with. So what can we do? I think we identify by our means - our method if you will. But the means I'm talking about is not "understanding." Certainly a lot of what we do is create knowledge, and that's important, but that's not all we do and not all we can do. Instead, I think "working with" is what defines anthropology. As Tim Ingold so eloquently explains in the epilogue of his book Being Alive, "working with" is what has defined anthropology from the very beginning (although that chapter begins with the phrase "The purpose of anthropology is to understand..." and is what sparked this post...). We work with people rather than study them or understand them. And it's this "working with" that creating a better world is all about. It's when we stop "working with" that we end up degenerating and making the world worse than it ever was before. The world needs more working with from anthropologists and everyone.