Practically speaking, by heading to the edge of chaos without going further, a leader may act spontaneously yet without disaster.

Both are quiet, contemplative, and very rational persons, not liable to act spontaneously.

To act spontaneously because it's the easiest thing to do in an argument.

They would not accept that the students could act spontaneously and have their own views outside of the party's direction.

It was the right thing to do evidently; acting spontaneously, he had performed an inspired action.

They have been known to act spontaneously, even to speak, but usually what they say is incoherent, or totally irrelevant to human interests.

This is, on the contrary, a museum in which people spontaneously act upon the wish to hold hands.

Cliff, acting spontaneously, beat the gang leader to the shot.

At the same time, he knew he would feel more free to act spontaneously without Hunter.

Neither is an intellectual kind of hero: both act naturally and spontaneously from the heart.