 While one occasionally finds in the literature the suggestion that physicalists are committed to (9) in fact, no physicalist since before Smart (1959) has (unqualifiedly) held anything like it. Adapting Ryle (1949), Smart supposed that in addition to physical expressions there is a class of expressions which are topic-neutral, i.e. expressions which were neither mental nor physical but when conjoined with any theory would greatly increase the expressive power of the theory. Smart suggested that one might analyze mental expressions in topic-neutral (but not physical) terms, which in effect means that a physicalist could reject (9).