A nomological dangler refers to the occurrence of something (in this case a sensation) that does not fit into the system of established laws. Smart believes that it is absurd that everything can be explained by the laws of physics except consciousness. He identifies consciousness with the broad term "sensations".
A nomological dangler refers to an event (in this case, a sensation) that defies the established laws of the system. Smart posits that it is illogical that everything can be explained by physical laws except consciousness, which he equates with the broader term "sensations".