Now if it be enquired, how this corrupt habit, or inclination to sin, is contracted? the corruption of nature necessarily ensues on the privation of original righteousness. Some have illustrated this by an apt similitude, taken from the travellers wandering out of his way, or taking a wrong path, as occasioned by the darkness of the night, in which, his want of light is the occasion, though not properly the cause of his wandering. Thus man is destitute of original righteousness, or those habits of supernatural grace, which are implanted in regeneration; and what can be the consequence thereof, but that his first actions, as soon as he is capable of doing good or evil, must contain in them nothing less than a sin of omission, or a defect of, and disinclination to, what is good? and, by this means, the soul becomes defiled, or inclined to sin; so that we first suppose it indisposed to what is good, and that this arises from its being destitute of supernatural grace, which it lost by Adam’s fall, and that God may deny this grace, without supposing him to be the author of sin; for he was not obliged to continue that to Adam’s posterity, which he forfeited, and lost for them. And that which follows, from hence, is, that the heart of man, by a continuance in sin after it is first tinctured with it, grows worse and worse, and more inclined to it than before. This I cannot better illustrate, than by comparing it to a drop of poison, injected into the veins of a man, which will by degrees corrupt the whole mass of blood.