There is a discernible performance difference between a Porsche and a Civic.

“[…] It’s for life, Miss Archer, it’s for life,” Lord Warburton repeated in the kindest, tenderest, pleasantest voice Isabel had ever heard, and looking at her with eyes charged with the light of a passion that had sifted itself clear of the baser parts of emotion—the heat, the violence, the unreason—and that burned as steadily as a lamp in a windless place.

The meaning of tianli here is perhaps closer to something like, “spontaneous (nonfabricated, nonarranged, nonteleological) coherence.”

Stayed in her own house, searched her body each morning and examined her conscience each night for progressive symptoms of the metastasis she feared was in her.