For more than two thousand years, one of the great questions in Western philosophy has been simple to ask and hard to answer:
What is the good life?
The ancient Greeks often framed the question around a telos, an ultimate end or goal. Aristotle’s answer was eudaimonia, a flourishing in my writing. He was not talking about a happy mood. He meant living and functioning well across a complete life through virtue and wisdom.
The philosophers who followed did not simply abandon the question; they argued over what flourishing required. The Stoics tied eudaimonia to virtue and living in accordance with nature. Epicurus put pleasure at the center, but not reckless indulgence. Same broad question. Very different answers.
Modern philosophy shifted the emphasis. Kant put moral duty and universal principles ahead of simply pursuing happiness, although happiness never disappeared. Bentham and Mill turned attention toward consequences and overall welfare. Later, ethics was increasingly organized around competing approaches such as duty and consequences, while the older question of character and the flourishing life moved more into the background. Then, beginning in the late 1950s, virtue ethics came roaring back.
The virtue revival continues today. Amartya Sen and Martha Nussbaum developed the Capabilities Approach, shifting attention toward the real opportunities people have to live lives they have reason to value. Psychology and social science have also begun measuring flourishing through things like health, relationships, and functioning well. This is where TST enters the long story. I am not inventing flourishing out of thin air. TST inherits one of philosophy’s oldest answers and extends its scope to flourishing for all.