Keynes's diagnosis of the Great Depression was a shortfall of aggregate demand. His solution was for the central government to borrow money, by selling bonds, in order to increase aggregate demand. Much of that would come from hiring people to build public goods such a roads and parks.

Beyond Keynes, there is a "democratically distributed income." That would create a bulletproof income that would sustain the economy, preventing any possibility of a depression. Unemployment and poverty would be eliminated permanently.

The DDI would not be paid to all citizens, but any (adult) citizen could become eligible for it. The money for the income would be free. It would be created as needed. The total of that income would be the supply of money (as currency) for the economy. (There would be built-in safeguards against inflation.)

"For Crying Out Loud, Accept That A Solution Actually Exists" (a "3 min read" — including options for further reading — here in Medium)