The article discusses how Marx's theories on capitalist exploitation and historical accounts of exploitation by merchants and usurers differ. These accounts belong to different levels of analysis: theoretical and historical. The significance of the law of value in history relates to the nature of exploitation. There are issues in Marx's work regarding how he derived the law of value and the transformation of money into capital. By reformulating these sections, the problems surrounding Marx's concept of capitalist exploitation without the capitalist mode of production can be resolved.