Of God and His Creatures

Even the motion of the whole universe may be regarded as one stupendous particular case of motion. Left to physical causes alone, the universe must run down like a clock, all positions of advantage being lost, all potential energy being converted into kinetic, one uniform temperature and one dead equilibrium of forces coming to obtain everywhere. This is an argument that motion and time must have had a beginning. Had the universe been at work from eternity, its capacity of work would have been exhausted ere now.

Of God and His Creatures: 2.33