Electronic edition published by Cultural Heritage Langauge Technologies (with permission from Charles Scribners and Sons) and funded by the National Science Foundation International Digital Libraries Program. This text has been proofread to a low degree of accuracy. It was converted to electronic form using data entry.
HUTTON, JAMES (b. Edinburgh, Scotland, 3 June
1726; d. Edinburgh, 26 March 1797), geology, agriculture,
physical sciences, philosophy.
Interest in various branches of the earth sciences
was then widespread, but recognition of geology as
an individual science had scarcely begun. The mining
of economic minerals was one of the oldest industries,
but the development of scientific mineralogy was
retarded by the undeveloped state of chemistry and
crystallography. Nevertheless, through mining and
quarrying operations, a knowledge of stratigraphy
must have been acquired locally, but it remained rudimentary
because of the almost universal belief that
the fossiliferous sediments had been deposited by, or
during the retreat of, the Noachian flood. While fossils
themselves had long aroused interest (it was recognized
that some forms could not be matched by
known living species) their value as chronological and
stratigraphic indexes had not yet been recognized
except, perhaps, over very limited local stratigraphic
ranges.
Crystalline rocks such as granite and gneiss, usually
found in the core of mountain ranges, were regarded
as primeval in age, and the sediments, often fossiliferous,
on the flanks of the mountains and in low
ground were assumed to be flood deposits. This classification
carried no implication that any rocks were
older than the five or six thousand years allowed for
in biblical chronology. By about the middle of the
eighteenth century, however, one or two authors had
suggested that geological time might be longer than
this chronology allowed. The effects of erosion, long
recognized, formed a subject for debate over whether
denudation would ultimately render the earth uninhabitable,
or whether it would be compensated by
the elevation of new lands on which life would continue.
There existed one major gap in geological knowledge.
It was unsuspected that rocks of the type now
classed as igneous formed a major and widely distributed
rock group, wholly distinct in origin from
the sediments. The extrusion of lava from active
volcanoes was looked on as a local and superficial
phenomenon. After about 1740, Italian and French
naturalists recognized the existence, locally, of volcanic
cones and lava flows in areas where there was
no record of volcanic activity in historic times; but
many years passed before it was realized that volcanic
activity had been worldwide, not only in historic
times but in past geologic ages. The igneous origin
of many rocks interbedded in, or otherwise closely
associated with, the sediments was still unrecognized.
Broadly speaking, the position was that many
geological observations had been made and recorded
in the literature; but previous attempts to synthesize
these observations into a general “theory of the
earth” were unscientific and had not proved acceptable.
The issue had been confused and progress retarded
by a literal belief in the biblical account of
creation and the universal flood.
The Theory of the Earth.
Hutton's theory, or “System
of the Earth,” as he called it originally, was first
made public at two meetings of the Royal Society
of Edinburgh, early in 1785. The society published
it in full in 1788, but offprints of this paper were in
circulation in 1787, and possibly in 1786. The theory
first appeared in print in condensed form, in a thirtypage
pamphlet entitled Abstract of a Dissertation ...
Concerning the System of the Earth, Its Duration, and
Stability, which Hutton circulated privately in 1785.
The interest of this pamphlet is that it states all the
conclusions which were essential to the theory as a
whole. It emphasizes that even at this early date
Hutton's thinking was far ahead of that of his contemporaries.
For this reason, and because it is more
easily comprehended than the full version, it is summarized
here.
Hutton's approach in the Abstract is logical, but
his thought is not translated into clear and incisive
prose. As with almost all that he wrote (other than
private letters), his style is prolix and abstruse, so that
the text must be read with care to appreciate its full
significance.
Hutton describes briefly his purpose in carrying out
the inquiry, the methods he employed in reaching
his conclusions, and the conclusions themselves. His
purpose was to ascertain (a) the length of time the
earth had existed as a “habitable world”; (b) the
changes it had undergone in the past; and (c) whether
any end to the present state of affairs could be foreseen.
He stated that the facts of the history of the
earth were to be found in “natural history,” not in
human records, and he ignored the biblical account
of creation as a source of scientific information (a
view he expressed explicitly later on). The method
he employed in carrying out his inquiry had been
a careful examination of the rocks of the earth's crust,
and a study of the natural processes that operated
on the earth's surface, or might be supposed, from
his examination of the rocks, to have operated in the
past. In this way, “from principles of natural philosophy,”
he attempted to arrive at some knowledge of
the order and system in the economy of the globe,
and to form a rational opinion as to the course of
nature and the possible course of natural events in
the future.
Hutton concluded that rocks in general (clearly he
referred here to the sedimentary rocks) are composed
of the products of the sea (fossils) and of other materials
similar to those found on the seashore (the products
of erosion). Hence they could not have formed