"Ever since, by his beloved brother's deathbed, Levin had first glanced
into the questions of life and death in the light of these new
convictions, as he called them, which had during the period from his
twentieth to his thirty-fourth year imperceptibly replaced his childish
and youthful beliefs- he had been stricken with horror, not so much of
death, as of life, without any knowledge of whence, and why,
and how, and what it was.

The physical organization, its decay, the Indestructibility of matter, the
law of the conservation of energy, evolution, were the words which usurped
the place of his old belief. These words and the ideas associated with
them were very well for intellectual purposes.

But for life they yielded nothing, and Levin felt suddenly like a man who
has changed his warm fur cloak for a muslin garment, and going for the
first time into the frost is immediately convinced, not by reason, but by
his whole nature, that he is as good as naked, and that he must infallibly
perish miserably"

Anna Karenin, Part 8, chapter VIII
Leo Tolstoy