Ricardo believed that this substance's function is only backed by the cost of labor necessary in extracting gold and silver.
Jane Jacobs distinguished between the "cataclysmic" and "gradual" forms of this material, arguing that the former is harmful for urban development. Another analysis of this substance claims that its impersonal nature allows it overcome distance in a rational matter. Karl Marx theorized that this sociological agent has the power to dissolve and create all bonds within a society. Georg Simmel's wrote a work about its aforementioned lack of emotional value. Ricardo believed that this substance's function is only backed by the cost of labor necessary in extracting gold and silver. For 10 points, identify this form of legal tender, which can be used as payment rendered for goods and services.
Jane Jacobs distinguished between the "cataclysmic" and "gradual" forms of this material, arguing that the former is harmful for urban development.
money [take any equivalents such as currency or legal tender]