This chapter shows that classically there is no satisfactory physical mechanism that sets the boundary of the mind. It also shows that functional and reductive approaches have opposing implications for the causal potency of conscious experiences and the ability of human consciousness to evolve. Historically, the compatibility between free will and determinism has been the subject of a prolonged controversy. Compatibilism is the position that free will and determinism are logically compatible, whereas incompatibilism is the alternative position that free will and determinism are logically incompatible. Classical reductionism avoids the hard problem by postulating that either the brain and the mind are identical or that certain physical observables of the brain are identical to the mind. Dualism postulates that both the brain and the mind exist but they are made of different substances. Thus, the brain is made of matter, whereas the mind is composed of conscious experiences.