 The situation becomes more complex, however, if we look at the principles which are to guide punishment. Rationales for punishment are often divided into those that are forward-looking and backward-looking. Forward-looking rationales include deterring crime, protecting society from dangerous persons, and rehabilitation of criminals. Backward-looking rationales normally focus on retribution, inflicting on the criminal harm comparable to the crime. Locke may seem to conflate these two rationales in passages like the following: