 The key question then is: If FP is a theory of everyday human psychology, is it a good theory? Some argue, given what we already know and are likely to discover, that is almost certainly a false theory. Some think it is so poor that we have reason to think the states over which it quantifies do not exist. Going by Churchland’s (1981) assessment, we have every reason to think FP’s principles are false and its ontology is an illusion. Churchland (1979, 1989, 1993) highlights FP’s lack of unity and fit with a growing body of theory elsewhere in the sciences. Others agree. Rosenberg (2018), for example, maintains that modern neuroscience directly refutes FP proposals about the true causes of human behavior.