Mind: A Brief Introduction (John R. Searle) / quote 41 of 138
Property dualism
There is a weaker version of dualism called “property dualism,” and that view is fairly widespread. The idea is this: Though there are not two kinds of substances in the world, there are two kinds of properties. Most properties, such as having an electrical charge, or having a certain mass, are physical properties; but some properties, such as feeling a pain or thinking about Kansas City, are mental properties. It is characteristic of human beings that though they are not composed of two different kinds of substances, their physical bodies, and in particular their brains, have not only physical properties, but mental properties as well. Property dualism avoids postulating a separate mental substance, but it inherits some of the difficulties of substance dualism. What are the relationships between the mental and the physical supposed to be? How is it that physical events can ever cause mental properties?