primum mobile

With him prayer was a thing of absolute necessity, and resignation to the eternal decrees the primum mobile of all.

The notion that there must be something immovable which moves all other things, is the old scholastic error of a primum mobile.

The primum mobile of the new system was Motion, in distinction from the Rest which marked the old monastic retreats.

In this effort lies its only possible unity, its primum mobile, its one clearly defined object from beginning to end.

Here it clearly refers to the primum mobile; it often applies to the whole expanse of the heavens.