For my money, Stephen Porges' Polyvagal Theory has done more to improve our ability to heal and grow and thrive as a civilization than any other scientific breakthrough of the past 50 years. Its advances over prior understandings of the human nervous system, psychology, and experiences of states like well-being, happiness, and love - are profound. Paradigm-shifting. And, unlike a lot of theory, incredible practical and applicable to our everyday lives.