a tax refers to a financial obligation imposed by a state on persons , whether natural or juridical , within its jurisdiction , for property owned , income earned , business or profession engaged in , or any such activity analogous in character for raising the necessary revenues to take care of the responsibilities of government.7 an often-quoted definition is that of cooley : `` taxes are the enforced proportional contributions from persons and property levied by the state by virtue of its sovereignty for the support of government and for all public needs .