The great design thinker Horst Rittel once wrote that “a design problem keeps changing while it is treated, because the understanding of what ought to be accomplished, and how it might be accomplished is continually shifting. Learning what the problem is IS the problem.”
Peter Hall, "A Good Argument," MetropolisMag.com, 18 Mar 2009, www.metropolismag.com/story/20090318/a-good-argument via Alan Blood.
