  Someone might object that the dean of the medical school does not qua dean hiccup in lectures. Qua dean he goes to meetings with the vice-chancellor. This is not to the point but there is a point behind it. This is that the property of being the professor of anatomy is not identical with the property of being the dean of the medical school. The question might be asked, that even if sensations are identical with brain processes, are there not introspected non-physical properties of sensations that are not identical with properties of brain processes? How would a physicalist identity theorist deal with this? The answer (Smart 1959) is that the properties of experiences are ‘topic neutral’. Smart adapted the words ‘topic-neutral’ from Ryle, who used them to characterise words such as ‘if, ‘or’, ‘and’, ‘not’, ‘because’. If you overheard only these words in a conversation you would not be able to tell whether the conversation was one of mathematics, physics, geology, history, theology, or any other subject. Smart used the words ‘topic neutral’ in the narrower sense of being neutral between physicalism and dualism. For example ‘going on’, ‘occurring’, ‘intermittent’, ‘waxing’, ‘waning’ are topic neutral. So is ‘me’ in so far as it refers to the utterer of the sentence in question. Thus to say that a sensation is caused by lightning or the presence of a cabbage before my eyes leaves it open as to whether the sensation is non-physical as the dualist believes or is physical as the materialist believes. This sentence also is neutral as to whether the properties of the sensation are physical or whether some of them are irreducibly psychical. To see how this idea can be applied to the present purpose let us consider the following example. 