Why Can We Copy Classical Information?

It is pointed out that the noncloning theorem in quantum mechanics also holds for unknown state in linear classical physics. The apparent capability of copying of a classical state is essentially the capability of perfect measurement in classical physics. The difference in copying between quantum and classical physics is the difference in measurement between the two theories. A classical copying process is the combined action of measurement of an unknown state and the preparation of this state onto another system. Hence perfect measurability in classical physics enables the copying of a classical state.