A brief summary of the views advocated by this eminent French geologist may serve to indicate, perhaps better than any general statements, the influences against which Lyell had to contend at the outset of his career as a geologist. With the omission of certain parts, to which no exception would be taken, or which have no very direct bearing upon the immediate question, they are as follows[65]: (1) In the history of the earth there have been long periods of comparative repose, during which the sedimentary strata have been continuously deposited, and short periods of paroxysmal violence, during which that continuity has been interrupted. (2) At each of these periods of violence or revolution in the state of the earth's surface, a great number of mountain-chains have been formed suddenly, and these chains, if contemporaneous, are parallel; but if not so, generally differ in direction. (3) Each revolution or great convulsion has coincided with the date of another geological phenomenon, namely, the passage from one independent sedimentary formation to another, characterised by a considerable difference in "organic types." (4) There has been a recurrence of these paroxysmal movements from the remotest geological periods; and they may still be produced. Thus the force of authority, which has to be reckoned with in geology, if not in other branches of science, was in the main adverse to Lyell, who could count on but few to join him in his attack on catastrophism. One indeed there was, a host in himself, who, though his contemporary in years, had devoted himself wholly to geology at a slightly earlier date and had already become convinced, by his field-work in Italy and France, of the efficacy of existing forces to work mighty changes, if time were given, in the configuration of the earth's surface. This was George Poulett Scrope, a man of broad culture, great talents, and singular independence of thought, who had convinced himself of the errors of the Wernerian theory by his studies in Italy in the years 1817-19, and had thoroughly explored the volcanic district of Auvergne in 1821. His work on the Phenomena of Volcanoes, published in 1823, and that on the Geology of Central France, published in 1826, had given the _coup de grace_ to Werner's hypothesis and had made the first breach in the fortress of the catastrophists.