Modes and mind

The traditional mind-body problem lives on as the problem of causal relevance: could a mental cause, qua mental, have a physical effect? The problem would resist formulation without appeal to properties-mental and physical properties. The difficulty is to understand how mental properties could make a difference in the physical world. It might seem that before we could solve this problem, we would need to ascertain the nature of properties. Consider two possibilities: (1) properties are what have traditionally been called modes or accidents and are nowadays called tropes; (2) properties are universals. Although there are good reasons to think that properties are modes, not universals, the distinction is largely irrelevant to recently proposed solutions to the problem of causal relevance.