the militant attack which has a method in doubting and whose rule of conduct has the motto More light."

66

It is a pleasure once more to acknowledge the helpfulness of the aid given me by Messrs. Chamberland and Roux during the studies I have just recorded. I wish also to acknowledge the great assistance of M. Doléris.

PREJUDICES WHICH HAVE RETARDED THE PROGRESS OF GEOLOGY

UNIFORMITY IN THE SERIES
OF PAST CHANGES

IN THE ANIMATE
AND INANIMATE WORLD

BY

SIR CHARLES LYELL

INTRODUCTORY NOTE

SIR CHARLES LYELL was born near Kirriemuir, Forfarshire, Scotland, on November 14, 1797. He graduated from Exeter College, Oxford, in 1819, and proceeded to the study of law. Although he practised for a short time, he was much hampered in this profession, as in all his work, by weak eyesight; and after the age of thirty he devoted himself chiefly to science.

Lyell's father was a botanist of some distinction, and the son seems to have been interested in natural history from an early age. While still an undergraduate he made geological journeys in Scotland and on the Continent of Europe, and throughout his life he upheld by precept and example the importance of travel for the geologist.

The first edition of his "Principles of Geology” was published in 1830; and the phrase used in the sub-title, “an attempt to explain the former changes of the earth's surface, by reference to causes now in action," strikes the keynote of his whole work. All his life he continued to urge this method of explanation in opposition to the hypotheses, formerly much in vogue, which assumed frequent catastrophes to account for geologic changes. The chapters here printed give his own final statement of his views on this important issue.

Lyell's scientific work received wide recognition: he was more than once President of the Geological Society, in 1864 was President of the British Association, was knighted in 1848, and made a baronet in 1864. He possessed a broad general culture, and his home was a noted center of the intellectual life of London. He twice came to the United States to lecture, and created great interest. On his death, on February 22, 1875, he was buried in Westminster Abbey.

Persistent as were Lyell's efforts for the establishment of his main theory, he remained remarkably open-minded; and when the evolutionary hypothesis was put forward he became a warm supporter of it. Darwin in his autobiography thus sums up Lyell's achievement: "The science of geology is enormously indebted to Lyell-more so, as I believe, than to any other man who ever ved."

THE PROGRESS OF GEOLOGY

I

PREPOSSESSIONS IN REGARD TO THE DURATION OF PAST TIME -PREJUDICES ARISING FROM OUR PECULIAR POSITION AS INHABITANTS OF THE LAND OTHERS OCCASIONED BY OUR NOT SEEING SUBTERRANEAN CHANGES NOW IN PROGRESS-ALL THESE CAUSES COMBINE TO MAKE THE FORMER COURSE OF NATURE APPEAR DIFFERENT FROM THE PRESENT OBJECTIONS TO THE DOCTRINE THAT CAUSES SIMILAR IN KIND AND ENERGY TO THOSE NOW ACTING, HAVE PRODUCED THE FORMER CHANGES OF THE EARTH'S SURFACE CONSIDERED

I'

F WE reflect on the history of the progress of geology *** we perceive that there have been great fluctuations of opinion respecting the nature of the causes to which all former changes of the earth's surface are referable. The first observers conceived the monuments which the geologist endeavours to decipher to relate to an original state of the earth, or to a period when there were causes in activity, distinct, in a kind and degree, from those now constituting the economy of nature. These views were gradually modified, and some of them entirely abandoned, in proportion as observations were multiplied, and the signs of former mutations were skilfully interpreted. Many appearances, which had for a long time been regarded as indicating mysterious and extraordinary agency, were finally recognised as the necessary result of the laws now governing the material world; and the discovery of this unlooked-for conformity has at length induced some philosophers to infer, that, during the ages contemplated in geology, there has never been any interruption to the agency of the same uni

1 The text of the two following papers is taken from the 11th edition of Lyell's Principles of Geology, the last edition revised by the author.

form laws of change. The same assemblage of general causes, they conceive, may have been sufficient to produce, by their various combinations, the endless diversity of effects, of which the shell of the earth has preserved the memorials; and, consistently with these principles, the recurrence of analogous changes is expected by them in time to come.

Whether we coincide or not in this doctrine we must admit that the gradual progress of opinion concerning the succession of phenomena in very remote eras, resembles, in a singular manner, that which has accompanied the growing intelligence of every people, in regard to the economy of nature in their own times. In an early state of advancement, when a greater number of natural appearances are unintelligible, an eclipse, an earthquake, a flood, or the approach of a comet, with many other occurrences afterwards found to belong to the regular course of events, are regarded as prodigies. The same delusion prevails as to moral phenomena, and many of these are ascribed to the intervention of demons, ghosts, witches, and other immaterial and supernatural agents. By degrees, many of the enigmas of the moral and physical world are explained, and, instead of being due to extrinsic and irregular causes, they are found to depend on fixed and invariable laws. The philosopher at last becomes convinced of the undeviating uniformity of secondary causes; and, guided by his faith in this principle, he determines the probability of accounts transmitted to him of former occurrences, and often rejects the fabulous tales of former times, on the ground of their being irreconcilable with the experience of more enlightened ages.

Prepossessions in regard to the duration of past time.—As a belief in the want of conformity in the cause by which the earth's crust has been modified in ancient and modern periods was, for a long time, universally prevalent, and that, too, amongst men who were convinced that the order of nature had been uniform for the last several thousand years, every circumstance which could have influenced their minds and given an undue bias to their opinions deserves particular attention. Now the reader may easily satisfy himself, that, however undeviating the course of nature may have been from the earliest epochs, it was impossible for the first cul