Definition of "insensibility"

What a deal of grief, care, and other harmful excitement does a healthy dulness and cheerful insensibility avoid!

1848 November – 1850 December, William Makepeace Thackeray, chapter 16, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

When I recovered I found myself lying on a clean, comfortable bed, while there bent over me a physician and an elderly woman. I learned that I had been found early in the morning in the rear of the house in a state of insensibility, and that the owner of the place […] had caused me to be brought in and placed on the bed.

1861, E. J. Guerin, Mountain Charley, page 27