That our land, which is now above the level of the sea, had been formerly under water, is a fact for which there is every where the testimony of a multitude of observations.  This indeed is a fact which is admitted upon all hands; it is a fact upon which the speculations of philosophers have been already much employed; but it is a fact still more important, in my opinion, than it has been ever yet considered.  It is not, however, as a solitary fact that any rational system may be founded upon this truth, That the earth had been formerly at the bottom of the sea; we must also see the nature and constitution of this earth as necessarily subsisting in continual change; and we must see the means employed by nature for constructing a continent of solid land in the fluid bosom of the deep.  It is then that we may judge of that design, by finding ends and means contrived in wisdom, that is to say, properly adapted to each other.

We have now given a theory founded upon the actual state of this earth, and the appearances of things, so far as they are changing; and we have, in support of that theory, adduced the observations of scientific men, who have carefully examined nature and described things in a manner that is clear and intelligible.  We are now to take a review of the principle points on which this theory hangs; and to endeavour to point out the importance of the subject, and the proper manner of judging with regard to a theory of the earth, how far it is conform to the general system of nature, which has for object a world.

If it should be admitted, that this earth had been formed by the collection of materials deposited within the sea, there will then appear to be certain things which ought to be explained by a theory, before that theory be received as belonging to this earth.  These are as follows: 

First, We ought to show how it came about that this whole earth, or by far the greatest part in all the quarters of the globe, had been formed of transported materials collected together in the sea.  It must be here remembered, that the highest of our mountainous countries are equally formed of those travelled materials as are the lowest of our plains; we are not therefore to have recourse to any thing that we see at present for the origin of those materials which actually compose the earth; and we must show from whence had come those travelled materials, manufactured by water, which were employed in composing the highest places of our land.

Secondly, We must explain how those loose and incoherent materials had been consolidated, as we find they are at present.  We are not here to allow ourselves the liberty, which naturalists have assumed without the least foundation, of explaining every thing of this sort by infiltration, a term in this case expressing nothing but our ignorance.

Thirdly, The strata are not always equally consolidated.  We often find contiguous strata in very different states with respect to solidity; and sometimes the most solid masses are found involved in the most porous substance.  Some explanation surely would be expected for this appearance, which is of a nature so conclusive as ought to attract the attention of a theorist.