The Theory of the Earth

Playfair informs us that Hutton “…was in no haste to publish his theory; for he was one of those who are much more delighted with the contemplation of truth, than with the praise of having discovered it”.It would take some 25 years to the first publication of an abstract to the Royal Society of Edinburgh in 1785, followed by full publication in 1788 and again in 1795.

The basic theme of Hutton’s theory is that the continents are repeatedly being wasted away (eroded), and simultaneously renewed by the operation of earth processes which are as evident now as they were in the past ie the erosion of rocks and soil and the transport of the eroded sediment to the sea; the uplift and subsidence of continents and volcanic activity are visible manifestations of the Earth operating as a machine fired by heat. An important aspect of the theory is that these processes took place over an indefinite space of time “…so that with respect to human observation, this world has neither a beginning nor an end”

This is Hutton’s own description of his theory from his abstract (1785);

“The solid parts of the present land appear in general, to have been composed of the productions of the sea, and of other materials similar to those now found upon the shores. Hence we find reason to conclude:

1st, That the land on which we rest is not simple and original, but that it is a composition, and had been formed by the operation of second causes.

2nd, That before the present land was made, there had subsisted a world composed of sea and land, in which were tides and currents, with such operations at the bottom of the sea as now take place. And,

Lastly, That while the present land was forming at the bottom of the ocean, the former land maintained plants and animals; at least the sea was than inhabited by animals, in a similar manner as it is at present.

Hence we are led to conclude, that the greater part of our land, if not the whole had been produced by operations natural to this globe; but that in order to make this land a permanent body, resisting the operations of the waters, two things had been required;

1st, The consolidation of masses formed by collections of loose or incoherent materials;

2ndly, The elevation of those consolidated masses from the bottom of the sea, the place where they were collected, to the stations in which they now remain above the level of the ocean.

Hutton realised that his theory raised two questions the answers to which would provide the proof for it, and in his abstract he continues:

“Thus the subject is considered as naturally divided into two branches, to be separately examined;

First, by what natural operation strata of loose materials had been formed into solid masses;

Secondly, By what power of nature the consolidated strata at the bottom of the sea had been transformed into land

What is remarkable and original about this “new and sublime conclusion” as Playfair described it, is that Hutton perceived the connection or continuity between these processes and on a global scale in terms of space, and a virtually infinite scale in terms of time; ie that rock and soil are eroded, that this eroded material is transported to the sea, where it is deposited, consolidated and elevated to form new land and that this cycle has taken place repeatedly during our planet’s past and will continue to do so into it’s future. Though the process is immeasurably slow in human terms, the surface of the earth has undergone transformation of gigantic proportions over a gigantic time-scale – and continues to do so! Thus he famously concluded when he published his theory in full (1788), “The result therefore of our present inquiry is that we find no vestige of a beginning – no prospect of an end”.