Note b — BOOK IV.

The infinite Creator hath generally exerted his Art and Care, in the Provision made by proper Muscles and Nerves, for all the different Motions in animal Bodies, both involuntary, and voluntary. It is a noble Providence that most of the vital Motions, such as of the Heart, Stomach, Guts, &c. are involuntary, the Muscles acting whether we sleep or wake, whether we will or no. And it is no less providential that some, even of the vital Motions, are partly voluntary, partly involuntary, as that for Instance, of Breathing, which is performed both sleeping and waking; but can be intermitted for a short Time on occasion, as for accurate hearing any Thing, &c. or can be encreased by a stronger Blast, to make the greater Discharges of the Blood from the Lungs, when that any Thing overcharges them. And as for the other Motions of the Body, as of the Limbs, and such as are voluntary, it is a no less Providence, that they are absolutely under the Power of the Will; so as that the Animal hath it in his Power to command the Muscles and Spirits of any part of its Body, to perform such Motions and Actions as it hath Occasion for.