Is science, as vital as it is, the end-all and be-all of humanity's space efforts?

I don't want to sound for one instant like I'm belittling the value of scientific discovery, but isn't our push into space also about what we take with us, rather than just what we can learn or bring back?

I've been thinking about this more since reading the transcript of Dr Zubrin's recent debate, wherein his opponent asked him what exactly on Mars is so valuable that bringing it back to earth would be worth the cost. IMHO, an enhanced understanding of our corner of the universe would be worth the price.

But the question he asked imposes a stark limit on the debate. There's also the question of what we can bring to Mars, or perhaps more properly what we can build there.

I know there are those who feel any "export of humanity" into space would be some sort of crime against the cosmos, but if we can agree on some basic points:

1. humanity as a whole is not inherently evil
2. we'll never achieve a perfect society

then we really might as well launch ourselves into the future immediately and whole-heartedly, and begin to accept that while not perfect, the human civilization that we'll take to the other planets--and eventually to the stars--also isn't all that horrible.

Humanity is what it is, whether by accident of chemistry or Godly design, and is worth nurturing and extending.

I've always beleived that our inevitable movement into the future is from one of two positions: either from ignorance or from knowledge, with the latter being the greatly preferred case. So trailblazing robots are certainly of incalculable value.

But by sending humans to follow those robots, in order to plant those first modest seeds that might eventually grow into an extension of our civilization beyond the earth, we'll be offering much to future generations.