Currency relative values of the different currencies. Currencies in this sense are defined by governments, and each type has limited boundaries of acceptance. Other definitions of the term "currency" are discussed in their respective synonymous articles banknote, coin, and money. The latter definition, pertaining to the currency systems of nations, is the topic of this article. Currencies can be classified into two monetary systems: fiat money and commodity money, depending on what guarantees the value (the economy at large vs. the government's physical metal reserves). Some currencies are legal tender in certain political jurisdictions. Others are simply traded for their economic
What Is it Like to Be a Bat? of experience, and the subjective character of experience cannot be explained by a reductionist being; it is a mental phenomenon that cannot be reduced to materialism. Thus for consciousness to be explained from a reductionist stance, the idea of the subjective character of experience would have to be discarded, which is absurd. Neither can a physicalist view, because in such a world each phenomenal experience had by a conscious being would have to have a physical property attributed to it, which is impossible to prove due to the subjectivity of conscious experience. Nagel argues that each and every subjective experience