The naturalists, who have so easily established families and vegetables, do not seem to have considered the whole extent of these consequences, which would reduce the immediate product of the creation, to any number of individuals however small; for, if it was once proved, that animals and vegetables were really divided into families, and that there was a single instance of one species having been produced by the degeneration of another; if it was true, that the ass was only a horse degenerated, there would be no bounds to the power of nature, and, we might, with equal reason suppose, that from one single individual being, in the course of time, she might have produced all the organized bodies which are now spread over the universe. But it is certain, by revelation, that all creatures have equally participated in the favours of creation; that the two first of each species, were formed by the hands of the Creator, and we ought to believe, that they were then nearly such as they appear at present in their descendants. Besides, since Nature has been observed with attention, from the time of Aristotle to the present, not a single new species has been seen, notwithstanding the rapid motion that drags on, or dissipates the parts of matter, notwithstanding the infinite number of combinations which must have been in the space of twenty centuries, notwithstanding the fortuitous couplings of different animals, from which nothing has ever resulted but vitiated and sterile individuals, and such as have not been able to become a stock for new generations. Were the exterior and interior resemblance in some animals still greater than they are between the horse and the ass, we ought not to confound these animals, nor give them to one common origin, for if they, in fact, came from the same stock, we might bring them back to their original state by new alliances, and undo by time, what time is already supposed to have done. We must also consider, that although nature proceeds by gradual, and frequently by imperceptible degrees, the intervals are not always the same. The more exalted the species, the fewer they are in number, and the shades by which they are separated, are more conspicuous; the smaller species, on the contrary, are very numerous, and have more affinity to each other, so that we are the more tempted to confound them together in the same family; but we should not forget that these families are our own works, that we have made them for the ease of our memories, that if we cannot comprehend the real relations of all beings, it is ourselves, not nature that is in fault, who knows not these pretended families; and, in fact, contains only individuals.