 In his First Defence, Clarke responds by giving an argument to show that there are no real emergent properties. He does this by giving an enumeration of all of the kinds of properties. It turns out that there are only three categories. These categories correspond roughly to the primary, secondary and tertiary qualities of the mechanical philosophy (Attfield 1977: 46). The correspondence is not precise because Clarke claims to be categorizing all properties, not just properties that belong to matter. Thus, he includes consciousness in the first category, though on a different basis than the first category properties of matter such as magnitude and motion. Clarke claims that only properties of the first kind are real. Properties of the second kind are 