Cameron Tonkinwise gives a talk on the necessary contradictions within lean design, citing some examples around waste, sustainability, and speed.
Toward the end of the talk, he defends design theory as a necessary means of packaging theoretical models to be transported into practice. If I understand him correctly, Cameron asserts that theory functions to create design patterns and principles that practitioners can use across many contexts. I must admit, this type of compartmentalizing of theory and practice is a little disconcerting. I'm not convinced that theoreticians can effectively spend their time observing and creating frameworks, while practitioners execute on these frameworks.
I think we need to leave some room for overlap. Practitioners (the good ones, anyway) are constantly reflecting and theorizing on their practice, and theorists (the good ones, anyway) will have some connections to the practical world in order to see their theories in use. While this is certainly not a new conversation, it's worth remembering. The line between design theory and practice isn't as bold as we sometimes think.