Moreover, I am not sure what working definition you are suggesting as an alternative, or why it is more useful.
I actually have my own eminently personal definition of progressivism, but it wouldn't be fair of me to impose it on political discourse.
The definition that I hope most people interested in substantive exchange in this field could agree on would be along the lines that it is a category of left-wing politics (ie, a politics whose guiding principle is equality) that wholeheartedly (if not necessarily uncritically) embraces Enlightenment thought (especially in its focus on the individual as the basic unit of political thought, and, yes, its belief that policies should be determined through rational means), and that deemphasizes the importance of a "final goal" to instead direct its attention toward what improvements can be achieved in the given context. Thus, the criteria that you use are a necessary condition to being progressive, but not a sufficient one.
