SECTION IV. OF PHYSICAL EVILS.
Physical evils are in nature inseparable from animal life, they commenced existence with it, and are its concomitants through life; so that the same nature which gives being to the one, gives birth to the other also; the one is not before or after the other, but they are coexistent together, and cotemporaries; and as they began existence in a necessary dependence on each other, so they terminate together in death and dissolution. This is the original order to which animal nature is subjected, as applied to every species of it. The beasts of the field, the fowls of the air, the fishes of the sea, with reptiles, and all manner of beings, which are possessed with animal life; nor is pain, sickness, or mortality any part of God's punishment for sin. On the other hand sensual happiness is no part of the reward of virtue: to reward moral actions with a glass of wine or a shoulder of mutton, would be as inadequate, as to measure a triangle with sound, for virtue and vice pertain to the mind, and their merits or demerits have their just effects on the conscience, as has been before evinced: but animal gratifications are common to the human race indiscriminately, and also, to the beasts of the field: and physical evils as promiscuously and universally extend to the whole, so "That there is no knowing good or evil by all that is before us, for all is vanity." It was not among the number of possibles, that animal life should be exempted from mortality: omnipotence itself could not have made it capable of eternalization and indissolubility; for the self same nature which constitutes animal life, subjects it to decay and dissolution; so that the one cannot be without the other, any more than there could be a compact number of mountains without vallies, or that I could exist and not exist at the same time, or that God should effect any other contradiction in nature; all contradictions being equally impossible, inasmuch as they imply an absolute incompatibility with nature and truth; for nature is predicated on truth, and the same truth which constitutes mountains, made the vallies at the same time; nor is it possible that they could have a separate existence. And the same truth which affirms my existence, denies its negative; so also the same law of nature, which in truth produceth an animal life and supports it for a season, wears it out, and in its natural course reduces it to its original elements again. The vegetable world also presents us with a constant aspect of productions and dissolutions; and the bustle of elements is beyond all conception; but the dissolution of forms is not the dissolution of matter, or the annihilation of it, nor of the creation, which exists in all possible forms and fluxilities; and it is from such physical alterations of the particles of matter, that animal or vegetable life is produced and destroyed. Elements afford them nutrition, and time brings them to maturity, decay and dissolution; and in all the prolific production of animal life, or the productions of those of a vegetative nature, throughout all their growth, decay and dissolution, make no addition or diminution of creation; but eternal nature continues its never ceasing operations, (which in most respects are mysterious to us) under the unerring guidance of the providence of God.
Animal nature consists of a regular constitution of a variety of organic parts, which have a particular and necessary dependance on each other, by the mutual assistance whereof the whole are animated. Blood seems to be the source of life, and it is requisite that it have a proper circulation from the heart to the extreme parts of the body, and from thence to the heart again, that it may repeat its temporary rounds through certain arteries and veins, which replenish every minutia part with blood and vital heat; but the brain is evidently the seat of sensation, which through the nervous system conveys the animal spirits to every part of the body, imparting to it sensation and motion, constituting it a living machine-, which could never have been produced, or exercised its respective functions in any other sort of world but this; which is in a constant series of fluxilities, and which causeth it to produce food for its inhabitants. An unchangeable world could not admit of production or dissolution, but would be identically the same, which would preclude the existence and nutriment of such sensitive creatures as we are. The nutrition extracted from food by the secret aptitudes of the digesting powers (by which mysterious operation it becomes incorporated with the circulating juices, supplying the animal functions with vital heat, strength and vigor) demands a constant flux and reflux of the particles of matter, which is perpetually incorporating with the body, and supplying the place of the superfluous particles that are constantly discharging themselves by insensible perspiration; supporting, and at the same time, in its ultimate tendency, destroying animal life. Thus it manifestly appears, that the laws of the world in which we live, and the constitution of the animal nature of man, are all but one uniform arrangement of cause and effect; and as by the course of those laws, animal life is propagated and sustained for a season, so by the operation of the same laws, decay and mortality are the necessary consequences.