Varieties of properties: an alternative distinction among qualities.

The traditional distinction between primary (observation independent) and secondary (observation dependent) qualities is not based on a difference that can be sustained in the full light of contemporary scientific understanding. An alternative division of physical and chemical properties is proposed. Like the traditional division of qualities, the alternative system has two main categories. Properties of compound particulars that result from simple combination (e.g., addition) of the properties of their component parts constitute the first class: properties that depend on details of interactions between component parts (e.g. cooperative effects) make up the second type. Application of the alternative dichotomy is considered for the cases of mass (traditionally a primary property) and color (a secondary quality, in the usual division). Both these types of properties can fall in either of the two classes of the alternate division of qualities, depending on the nature of the interaction that occurs between components. Both mass and color show that intermediate cases occur. Application of the alternative categorical scheme is straightforward, but not always simple. The proposed system shows that in chemical combination (and, perforce, in the many more complex systems common in human culture) interactions profoundly influence properties of entities that enter the interaction. This is not adequately treated by philosophical theories of wholes and parts (mereology), which should be extended to apply to such important cases.