Well, yeah, you can't create something from nothing. But that's not exactly a deep insight. All economic activity involves consumption if you want to cast the net that broadly.
The point is:
> The idea that people need to be encouraged to consume (consumption being the opposite of saving) I don't think is supported by economic theory.
People absolutely need to be encouraged to be productive. That's the whole point of an economy, to encourage people to produce things that others want in exchange for other people producing things that they want.
Honestly, how could anyone possibly not understand that?
