 Introspection is also central to philosophy of mind, both as a process worth study in its own right and as a court of appeal for other claims about the mind. Philosophers of mind offer a variety of theories of the nature of introspection; and philosophical claims about consciousness, emotion, free will, personal identity, thought, belief, imagery, perception, and other mental phenomena are often thought to have introspective consequences or to be susceptible to introspective verification. For similar reasons, empirical psychologists too have discussed the accuracy of introspective judgments and the role of introspection in the science of the mind.