Powerful Qualities or Pure Powers?

This paper explores the debate between those philosophers who take (fundamental, perfectly natural) properties to be pure powers and those who take them to be powerful qualities. I first consider two challenges for the view that properties are powerful qualities, which I call, respectively, ‘the clarification challenge’ and ‘the explanatory challenge’. I then examine a number of arguments that aim to show that properties cannot be pure powers and find them all wanting. Finally, I sketch what I take to be the most promising argument against pure powers and for powerful qualities.