The first need of a science in this state is the accumulation of facts, and most of the older geologists of the time, like Sedgwick, Murchison and Buckland, bent themselves to this task. But the man who dealt the death-blow to the old uncritical view of geology was Sir Charles Lyell, whose _Principles of Geology_ (1830-1833) marks an epoch in the science. Lyell's central doctrine is that the past history of the earth must be inferred by ordinary processes of observation and reasoning from the present, and that it is possible to interpret 'the testimony of the rocks' by means of principles which we still see at work. In other words, he was a 'uniformitarian.' The victory of his view established 'the reign of law' over the field of geology, and went far towards convincing men of its universality. Assuming no causes except such as he could point to in experience, Lyell showed how the geological formations of the earth arose. According to Darwin, the effect of Lyell's work could formerly be seen in the much more rapid progress of geology in England than in France; and the _Principles of Geology_ was most helpful to Darwin himself. In his _Antiquity of Man_ (1863) Lyell touched the verge of the problem of organic life. He did so in a spirit of open-minded conservatism. He had now to guide him the great light of the _Origin of Species_, and even before its publication he had had glimmerings of evolution. He saw that Darwin only extended to the animal and vegetable world his own central principle. But he felt a deep objection to tracing the descent of man through some ape-like creature, and hence, while _The Antiquity of Man_ recognises the long history of the race upon earth, it contains no avowal of belief in his descent from inferior forms of life. [Sidenote: Hugh Miller (1802-1856).] Another geologist, who was rather a popular expositor than a profound man of science, was Hugh Miller. Miller was bred as a mason, and it was in the quarries where he pursued his trade (quarrying being in his time and district associated with stone-cutting) that he laid the foundation of his geological knowledge. But Miller was more than a geologist. He threw himself energetically into the contest which culminated in the Scottish Disruption of 1843; and for the last sixteen years of his life he was editor of the bi-weekly paper, _The Witness_, which had been established by the leaders of the Free Church movement as the organ of their opinions. The sad close of Miller's life by suicide is well known. His health had been undermined by early hardships and by subsequent overwork, and an examination after death proved that the brain was diseased.