720 REPORT—1 899. 
history of the earth vast periods of time must be admitted to have elapsed, our 
debt of obligation to him is increased by the genius with which he linked the 
passage of these vast periods with the present economy of nature. He first 
realised the influence of time as a factor in geological dynamics, and first taught the 
efficacy of the quiet and unobtrusive forces of nature. His predecessors and con- 
temporaries were never tired of invoking the more vigorous manifestations of 
terrestrial energy. They saw in the composition of the land and in the structure 
of mountains and valleys memorials of numberless convulsions and cataclysms. 
In Hutton’s philosophy, however, ‘it is the little causes, long continued, which 
are considered as bringing about the greatest changes of the earth.’? 
And yet, unlike many of those who derived their inspiration from his teaching, 
but pushed his tenets to extremes which he doubtless never anticipated, he did not 
look upon time as a kind of scientific fetich, the invocation of which would endow 
with efficacy even the most trifling phenomena. Asif he had foreseen the use 
that might be made of his doctrine, he uttered this remarkable warning: ‘ With 
regard to the effect of time, though the continuance of time may do much in those 
operations which are extremely slow, where no change, to our observation, had 
appeared to take place, yet, where it is not in the nature of things to produce the 
change in question, the unlimited course of time would be no more effectual than 
the moment by which we measure events in our observations.’ * 
We thus see that in the philosophy of Hutton, out of which so much of 
modern geology has been developed, the vastness of the antiquity of the globe was 
deduced from the structure of the terrestrial crust and the slow rate of action of 
the forces by which the surface of the crust is observed to be modified. But no 
attempt was made by him to measure that antiquity by any of the chronological 
_ standards of human contrivance. He was content to realise for himself and to 
impress upon others that the history of the earth could not be understood, save by 
the admission that it occupied prolonged though indeterminate ages in its accom- 
plishment. And assuredly no part of his teaching has been more amply sustained 
by the subsequent progress of research. 
Playfair, from whose admirable ‘ Illustrations of the Huttonian Theory’ most 
geologists have derived all that they know directly of that theory, went a little 
further than his friend and master in dealing with the age of the earth. Not 
restricting himself, as Hutton did, to the testimony of the rocks, which showed 
neither vestige of a beginning nor prospect of an end, he called in the evidence of 
the cosmos outside the limits of our planet, and declared that in the firmament 
also no mark could be discovered of the commencement or termination of the 
present order, no symptom of infancy or old age, nor any sign by which the future 
or past duration of the universe might be estimated.’ He thus advanced beyond 
the strictly geological basis of reasoning, and committed himself to statements 
which, like some made also by Hutton, seem to have been suggested by certain 
deductions of the French mathematicians of his day regarding the stability of the 
planetary motions. His statements have been disproved by modern physics; dis- 
tinct evidence, both from the earth and the cosmos, has been brought forward of 
progress from a beginning which can be conceived, through successive stages to an 
end which can be foreseen. But the disproof leaves Hutton’s doctrine about the 
vastness of geological time exactly where it was. Surely it was no abuse of 
language to speak of periods as being vast, which can only be expressed in 
millions of years. 
It is easy to understand how the Uniformitarian school, which sprang from the 
teaching of Hutton and Playfair, came to believe that the whole of eternity was at 
the disposal of geologists. In popular estimation, as the ancient science of astro- 
nomy was that of infinite distance, so the modern study of geology was the science 
of infinite time. It must be frankly conceded that geologists, believing themselves 
unfettered by any limits to their chronology, made ample use of their imagined 
liberty. Many of them, following the lead of Lyell, to whose writings in other 
1 Theory of the Earth, vol. ii. p. 205. 2 Op. cit. vol. i, p. 44. 
3 Illustrations of the Huttonian Theory, § 118, 
