Abstract

There is a strong pull to the idea that there is some metaphysically interesting distinction between the fully real, objective, observer‐independent qualities of things as they are in themselves, and the less‐than‐fully‐real, subjective, observer‐dependent qualities of things as they are for us. Call this (putative) distinction the primary/secondary quality distinction. The distinction between primary and secondary qualities is philosophically interesting because it is (a) often quite attractive to draw such a distinction, and (b) incredibly hard to spell it out in any kind of satisfying and sensible way. I attempt such a spelling‐out after first trying to pin down in more detail what we want from the primary/secondary quality distinction, and saying a bit about why that is such a hard thing to get.