Skip to content

Georges Cuvier, “Preliminary Discourse” (1812)

Download the 1818 Jameson translation free from, read or download the Jameson translation at Forgotten Books, or buy the Rudwick translation in ebook form from or Google Books.

(if you don’t want to tackle the whole)

Georges Cuvier
“Preliminary Discourse”
translated by Robert Jameson

1. Preliminary Observations

…The ancient history of the globe…is also of itself one of the most curious subjects that can engage the attention of enlightened men; and if they take any interest in examining, in the infancy of our species, the almost obliterated traces of so many nations that have become extinct, they will doubtless take a similar interest in collecting, amidst the darkness which covers the infancy of the globe, the traces of thsoe revolutions which took place anterior to the existence of all nations.

We admire the power by which the human mind has measured the motions of globes which nature seemed to have concealed for ever from our view: Genius and science have burst the limits of space; and a few observations, explained by just reasoning, have unveiled the mechanism of the universe. Would it not also be glorious for man to burst the limits of time, and, by a few observations, to ascertain the history of this world, and the series of events which preceded the birth of the human race?…

 4. First Proofs of Revolutions on the Surface of the Globe

The lowest and most level parts of the earth, when penetrated to a very great depth, exhibit nothing but horizontal strata composed of various substances, and containing almost all of them innumerable marine productions. Similar strata, with the same kind of productions, compose the hills even to a great height….[T]he shells…are found in elevations far above the level of every part of the ocean, and in places to which the sea could not be conveyed by any existing cause….Every part of the earth, every hemisphere, every continent, every island of any size, exhibits the same phenomenon. We are therefore forcibly led to believe, not only that the sea has at one period or another covered all our plains, but that it must have remained there for a long time…

The traces of revolutions become still more apparent and decisive when we ascend a little higher, and approach nearer to the foot of the great chains of mountains. There are still found many beds of shells…but they are not of the same species with those which were found in the less elevated regions. The strata which contain them are not so generally horizontal: they have various degrees of inclination, and are sometimes situated vertically….These inclined or vertical strata…do not rest on the hoirzontal strata…but, on the contrary, are situated underneath them…The inclined strata are therefore more ancient than the horizontal strata. And as they must necessarily have been formed in a horizontal position, they have been subsequently shifted into their inclined or vertical position, and that too before the horizontal strata were placed above them.

Thus the sea, previous to the formation of the horizontal strata, had formed others, which, by some means, have been broken, lifted up, and overturned in a thousand ways….

 5. Proofs that such Revolutions have been numerous

If we institute a more detailed comparison between the various strata and those remains of animals which they contain, we shall soon discover still more numerous differences among them, indicating a proportional number of changes in their condition. The sea has not always deposited stony substances of the same kind….Thus the great catastorphes which have produced revolutions in the basin of the sea, were preceded, accompanied, and followed by changes in the nature of the fluid and of the substances which it held in solution…

Amidst these changes of the general fluid, it must have been almost impossible for the same kind of animals to continue to live….Their species, and even tehri genera, change with the strata…In animal nature, therefore, there has been a succession of changes corresponding to those which have taken place in the chemical nature of the fluid…

…[T]he various catastrophes of our planet have not only caused the different parts of our continent to rise by degrees from the basin of the sea, but it has also frequently happened, that lands which had been laid dry have been again covered by water…The changes which have taken place in the products of the shelly strata have not…been entirely owing to a gradual and general retreat of the waters, but to successive irruptions and retreats…

 6. Proofs that the Revolutions have been sudden

These repeated irruptions and retreats of the sea have neither been slow nor gradual; most of the catastrophes which have occasioned them have been sudden; and this is easily proved, especially with regard to the last of them, the traces of which are most conspicuous. In the northern regions it has left the carcasses of some large quadrupeds which the ice had arrested, and which are preserved even to the present day with their skin, their hair, and their flesh. If they had not been frozen as soon as killed they must quickly have been decomposed by putrefaction. But his eternal frost could not have taken possession of the regions which these animals inhabited except by the same cause which destroyed them; this cause, therefore, must have been as sudden as its effect. The breaking to pieces and overturnings of the strata, which happened in former catastrophes, shew plainly enough that they were sudden and violent like the last…

Life, therefore, has been often disturbed on this earth by terrible events—calamities which, at their commencement have perhaps moved and overturned to a great depth the entire outer crust of the globe, but which, since these first commotions, have uniformly acted at a less depth and less generally. Numberless living beings have been the victims of these catastrophes; some have been destroyed by sudden inundations, others have been laid dry in consequence of the bottom of the seas being instantaneously elevated. Their races even have become extinct, and have left no memorial of them except some small fragment which the naturalist can scarcely recognize.

Such are the conclusions which necessarily result from the objects that we meet with at every step of our inquiry, and which we can always verify by examples drawn from almost every country. Every part of the globe bears the impress of these great and terrible events so distinctly, that they must be visible to all who are qualified  to read their history in the remains which they have left behind….

 34. Concluding Reflections

I am of opinion…that, if there is any circumstance thoroughly established in geology, it is, that the crust of our blog has been subjected to a great a sudden revolution, the epoch of which cannot be dated much farther back than five or six thousand years ago; that this revolution had buried all the countries which were before inhabited by men and by the other animals that are now best known; that the same revolution had laid dry the bed of the last ocean, which now forms all the countries at present inhabited; that the small number of individuals of men and other animals that escaped from the effects of that great revolution, have since propagated and psread over the lands then newly laid dry; and consequently, that the human race has only resumed a progressive state of improvement since that epoch, by forming established societies, raising monuments, collecting natural facts, and constructing systems of science and of learning.

Yet farther,—That the countries which are now inhabited, and which were laid dry by this last revolution, and been formerly inhabited at a more remote era, if not by man, at least by land animals; that, consequently, at least one previous revolution had submerged them under the waters; and that, judging from the different orders of animals of which we discover the remains in a fossil state, they had probably experienced two or three irruptions of the sea…

It would certainly be exceedingly satisfactory to have the fossil organic productions arranged in chronological order, in the same manner as we now have the principal mineral substances. By this the science of organization itself would be improved; the developments of animal life; the succession of its forms; the precise determinations of those which have been first called into existence; the simultanous production of certain species, and their gradual extinction;—all these would perhaps instruct us fully as much in the essence of organization, as all the experiments that we shall ever be able to make upon living animals: And man, to whom only a short space of time is allotted upon the earth, would have the glory of restoring the history of thousands of ages which preceded the existence of the race, and of thousands of animals that never were contemporaneous with his species.

Go back to the main Story of Science page.