But though it is certain that Lyell did not derive his evolutionary views from Hutton, yet when he came to write his historical introduction to the Principles, he was greatly impressed by the proofs of genius shown by the great Scotch philosopher, and equally by the brilliant exposition of those views by Playfair in his Illustrations. To the former he gave unstinted praise for the breadth and originality of his views, and to the latter for the eloquence of his writings—adopting quotations chosen from these last, indeed, as mottoes for his own work.

It is only just to add that for the violent prejudices excited by some of his contemporaries against Hutton's writings—as being directed against the theological tenets of the day and therefore subversive of religion—there is really no foundation whatever; and every candid reader of the Theory of the Earth must acquit its author of any such design. The passage quoted on page 51 could only have been written by Lyell at a time when he was still unacquainted with Hutton's works, and was misled by common report concerning them. It is interesting to note, however, that the passage occurs in a letter written in December 1827, that is after the first draft of the Principles of Geology had been 'delivered to the publisher,' and before the preparation of the historical introduction, which would appear to have led to the first perusal of Hutton's great work, and that of his brilliant illustrator, Playfair.

CHAPTER VI

'THE PRINCIPLES OF GEOLOGY'

We have seen that as early as the year 1817, when he visited East Anglia, Lyell began to experience vague doubts concerning the soundness of the 'Catastrophist' doctrines, which had been so strongly impressed upon him by Buckland. And these doubts in the mind of the undergraduate of twenty years of age gradually acquired strength and definiteness during his frequent geological excursions, at home and abroad, during the next ten years. At what particular date the design was formed of writing a book and attacking the predominant beliefs of his fellow-geologists, we have no means of ascertaining exactly; but from a letter written to his friend Dr Mantell, we find that at one time Lyell contemplated publishing a book in the form of 'Conversations in Geology[42],' without putting his name to it. This was probably suggested by the manner in which Copernicus and Galileo sought to circumvent theological opposition in the case of Astronomical Theory.

But this plan appears to have been soon abandoned; and by the end of the year 1827, when he had reached the age of thirty, Lyell had sent to the printer the first manuscript of the Principles of Geology, proposing that it should appear in the course of the following year in two octavo volumes[43].

A great and sudden interruption to this plan occurred however, for just at this time Lyell was engaged in writing his review for the Quarterly of Scrope's work on The Geology of Central France, and while doing this his interest was so strongly aroused by the accounts of the phenomena exhibited in the Auvergne, that he was led for a time to abandon the task of seeing his own book through the press; and, having induced Murchison and his wife to accompany him, set off on a visit to that wonderful district. He also felt that, before completing the second part of his book, he needed more information concerning the Tertiary formations, especially in Italy.

Lyell had been very early convinced of the supreme importance of travel to the geologist. In a letter to his friend Murchison he said:—'We must preach up travelling, as Demosthenes did "delivery" as the first, second and third requisites for a modern geologist, in the present adolescent state of the science[44].'

And Professor Bonney has estimated that so far did he himself practise what he preached, that no less than one fourth of the period of his active life was spent in travel[45].