Kurt Lewin famously said “There is nothing so practical as a good theory.” In the past two decades, this quote has been cited hundreds if not thousands of times in the literature, but in recent years there has been renewed attention to the problems of a theory-practice gap and how to resolve it. Yet since 2000 there has been a lot of attention paid to closing the ‘gap’ between theory and practice to limited avail? So was Lewin right, or is something else wrong?

In this talk, I argue the latter -- mainly that we are being misled by the very metaphors we use to describe the differences between theory and practice. I offer a different metaphor from the 'gap.' This alternative metaphor -- that of the 'rheostat' -- suggests some theories are simply not meant to be practical, but they are still good theories. Meanwhile, the inverse is also true in that certain matters of practice have little business being theorized. Below is a graphic, referenced in the episode, that shows how the rheostat metaphor works.