The energy of spiraling economies

I had a problem understanding Keynes because of my usual complaint,  one cannot develop an ongoing deflationary shock in a leakless model.  In other words, one has to leave the realm of measurement economics to get an ongoing deflationary spiral, and that is where Animal Spirits come in.   I saw the new cartoon on the subject.  The cartoon suddenly explained that Animal Spirits are a growing, non-economic force internal to the agent, a persistent devolution.