What assumptions are made in the Neoclassical model that lead to the conclusion that the economy does contain a self-correcting mechanism. And, how

What assumptions are made in the Neoclassical model that lead to the conclusion that the economy does contain a self-correcting mechanism. And, how exactly does the self-adjustment work? That is, what variables or curves change, and why, that lead an economy away from a disequilibrium and back toward full employment?