Henri Bergson called it the élan vital, a force that drives life forward. Science dropped the force, but I keep the phrase. What drives me is no mystical force. It is the seeking system, the itch to explore and expect, and flourishing is where I point it.
I point it six ways:
The first three are the three realms, and my ranking of them is still temperament. Flourishing does not mean equal effort. It means none of the six goes dark. Humor and spiritual depth are my additions, and the standard catalog of character strengths files both under transcendence.
The practice is a loop. Refine what the six mean to me. Pursue them with courage and humility, head up. Accept that I will never arrive, since things fall apart and the hedonic treadmill resets every gain. Watch for distraction and drift, which is the pause at work, and realign with my values. Then start again, because desires change.
What matters is direction, not arrival.