Presence of mind

[A]s you are to hear the moſt unexpected and ſurprizing thing that perhaps ever befel any Family in the VVorld, I beg you to promiſe me you vvill receive it vvith Compoſure and a Preſence of Mind ſuitable to a Man of Senſe.

[T]his magnificent palace would have infallibly been burnt down to the ground, if, by a presence of mind unusual to me, I had not suddenly thought of an expedient.

[S]he snatched a pistol from the wall, on which some fire-arms hung, and while she screamed to her father to awake, had the presence of mind to present it at the intruder.

The Major and Captain Costigan were old soldiers and accustomed to face the enemy, so we may presume that they retained their presence of mind perfectly; but the rest of the party assembled in Cos's sitting-room were, perhaps, a little flurried at Pendennis's apparition.

During the whole agitating scene, Lillie kept up her presence of mind, and was perfectly aware of what she was about; […]

It speaks well for Barrett's presence of mind that he had grasped the situation and decided on his line of action before Welch went, and the Head turned his attention to him.

Somebody had the presence of mind to give [Christopher] Reeve mouth-to-mouth resuscitation, and the paramedics arrived about a minute later.

He slipped and fell under the wagon's wheels, losing his left leg. His presence of mind was quite amazing. The report notes that Webb's knowledge of first aid probably saved his life, and he was able to instruct others who came to help him.