Both Uses of

persistence
in
The Magic Mountain

You see, what confuses the world is the incongruity between the swift flight of the mind and matter's vast clumsy slowness, its dogged persistence and inertia.†
Chpt 6.8 *

After that, he threw himself with redoubled fervor into the arms of the clear-eyed goddess, about whose soothing powers Director Behrens had so many virtuous things to say; and the problem that consumed his every thought day and night, to which he devoted all the persistence, all the sportsman's tenacity he had once brought to the conviction of poor sinners—back in the days before his frequently extended leave of absence, which now threatened to become permanent retirement—that problem was nothing less than the squaring of the circle.†
Chpt 7.6

Definition:

continuing or repeating behavior -- especially in spite of difficulties

or:

continuing or prolonged existence of something