Can human spaceflight be justified?

On the 20th anniversary of the launch of the Hubble Space Telescope, the Atlantic Monthly just published a great article in which the following series of questions were posed:

"So in the highly segmented world of NASA, is the Hubble a triumph and justification for human space flight? Or proof that we can be equally thrilled, excited and humbled by our robotic explorations in space...and proof of how much more we can learn from non-human voyages and missions?"

http://www.theatlantic.com/science/archive/2010/04/20-years-later-hubble-humans-and-the-future-of-space-flight/39212/

Former NASA astronaut Story Musgrave has an interesting perspective on these questions.

What's your take?