spontaneity

1. The quality or condition of being spontaneous.
2. Spontaneous behavior, impulse, or movement.

noun

Freedom from constraint, formality, embarrassment, or awkwardness: casualness, ease, easiness, informality, naturalness, poise, unceremoniousness, unrestraint. See restraint/unrestraint, tighten/loosen.

The noun has one meaning:

Meaning #1: the quality of being spontaneous and coming from natural feelings without constraint
  Synonym: spontaneousness

Quotes:

"Our spontaneous action is always the best. You cannot, with your best deliberation and heed, come so close to any question as your spontaneous glance shall bring you." - Ralph Waldo Emerson

"Improvisation is too good to leave to chance." - Paul Simon

"Through spontaneity we are re-formed into ourselves. It creates an explosion that for the moment frees us from handed-down frames of reference, memory choked with old facts and information and undigested theories and techniques of other people's findings. Spontaneity is the moment of personal freedom when we are faced with reality, and see it, explore it and act accordingly. In this reality the bits and pieces of ourselves function as an organic whole. It is the time of discovery, of experiencing, of creative expression." - Viola Spolin