 One strategy would be to turn to the basic ontology of one’s causal theory of mental content. This is where a theory based on nomological relations might be superior to a version that is based on causal relations between individuals. One might say that there can be a unicorn-“unicorn” law, even if there are no actual unicorns. This story, however, would break down for mental representations of individuals, such as the putative planet Vulcan. There is no law that connects a mental representation to an individual; laws are relations among properties.