A herd of goats and an apple orchard both exhibit exponential growth in production, to the limits of the supporting land (which admittedly may be reached rather quickly). Indeed this is the origin of interest: I lend you my goats for a season and expect to get back a larger herd. The argument that non-capitalist economies can't have exponential growth from investment is a non-starter.

Good thing nobody made that argument! My argument was that you can't hide goats.