 Parsons’ theory is based on the Meinongian distinction between nuclear and extra-nuclear properties. Nuclear properties include all ordinary properties, such as being blue, being tall, being kicked by Socrates, being a mountain, and so on. Extra-nuclear properties include ontological properties such as existence and being fictional, modal properties such as being possible, intentional properties such as being thought of by Socrates, and technical properties such as being complete. See Parsons 1980: 24–27, 166–74 for more on nuclear and extra-nuclear properties and a test for distinguishing between them. Parsons’ theory can be encapsulated in the following two principles: