In this chapter, Rohatinski turns to the evolution economic theory, establishing the foundations for an understanding of how time affects economic activity. Looking at the historic character of economic activity, the author examines narrow and broad concepts of what comprises economic activity. Particular attention is paid to the ideas presented by Karl Marx in Capital and other writings. Rohatinski observes that economic activity is a multi-valued and complex paradigm and includes a relatively broad range of material and social aspects, as well as content. The social character of economic activity reveals that just as society changes over time, the content, form, and properties evolve in parallel.