Which preposition to use with endlessness

of Occurrences 6%

When we gain access to the histories of China and of India, the endlessness of the subject-matter will reveal to us the defects in the study, and force our historians to see that the object of science is to recognize the many in the one, to perceive the rules in any given example, and to apply to the life of nations a knowledge of mankind; not to go on counting up facts ad infinitum.

in Occurrences 1%

Because of this endlessness in the series there is no first or ultimate cause in the phenomenal world; all finite causes are second causes; the primary cause lies within the sphere of the infinite and is God himself.

Which preposition to use with  endlessness