History is the science which investigates the successive changes that have taken place in the material and intellectual conditions of man; it inquires into the causes of those changes, and the influence which they have exerted in modifying the life and mind of mankind.

This is a theoretical paper. A little theory goes a long way in history, for me; but it is good to collect as much as is feasible in one paper, so that gaps and inconsistencies can be noticed. I use ‘theory’ in the definite sense of a set of hypothetical statements such that deductions can be made and compared with data, facts, or generalizations obtained in some other way than as derivation from theory. Deductions need not always be rigorous, and there may be two or more ‘solutions’ obtainable, of which the scientist may choose one and discard the rest (for example, he may discard all ‘imaginary’ solutions). I am ignoring the differences between propositions, demonstrations, problems, and the like. Actually there must always be several statements, including rules of procedure, in the set; but often many are assumed and only the new or controversial one is stated as ‘the’ hypothesis of Mr X.

Two of the most influential evaluations of Charles Lyell's geological ideas were those of the philosophers of science, John F. W. Herschel and William Whewell. In this paper I shall argue that the great difference between these evaluations—whereas Herschel was fundamentally sympathetic to Lyell's geologizing, Whewell was fundamentally opposed—is a function of the fact that Herschel was an empiricist and Whewell a rationalist. For convenience, I shall structure the discussion around the three key elements in Lyell's approach to geology. First, he was an actualist: he wanted to explain past geological phenomena in terms of causes of the kind that are operating at present. Second, he was a uniformitarian: he wanted to explain only in terms of causes of the degree operating at present; that is, he wanted to avoid ‘catastrophes’. Third, as a geologist he saw the earth as being in a steady-state, in which all periods are essentially similar to one another. Because they will prove important, I draw attention also to two major features of Lyell's programme. First, there is his theory of climate, which suggests, ‘without help from a comet’, that earthly temperature fluctuations are primarily a function of the constantly changing distribution of land and sea. Clearly this theory is actualistic, for it is based on such present phenomena as the Gulf Stream; it is also uniformitarian and supports a steady-state world picture. Second, there is Lyell's denial that the fossil record is progressive, his criticism of Lamarckian evolutionism, ostensibly on the grounds that modern evidence is against it (i.e. it fails actualistically), and his rather veiled claim that the origins of species will nevertheless prove in some way natural, that is, subject to causes falling beneath lawlike regularities in principle discernible by us.

In offering a contribution to a session concerned with ‘the background to Lyell's work’, I want to begin by launching a caveat against the notion of ‘background’. If, in the case of Lyell, ‘background’ features remained in obscurity then they can be dismissed; if, however, ‘background’ features were important then they become foreground. This point is not merely linguistic pedantry, because if we look at the scientific institutions of London in the period 1820–41, it is too easy to assume, with naïve optimism, that if they existed they must have been functionally effective for scientists. This was not necessarily so. We have to discover, as a matter of contingent reality, the ways in which particular institutions actually affected the careers of individual scientists. In this paper, therefore, I shall offer some general observations on London scientific institutions; and then I shall analyse Lyell's varying allegiances to them in terms of his ambitions concerning the shape and direction of his career.

For many of those who attended the Charles Lyell Centenary Symposium, one of the high points was the reappearance of Lyell himself (ably impersonated by John Thackray) in the lecture theatre of the Royal Institution, where some extracts from his London lectures of 1832–3 gave a vivid demonstration of his persuasive rhetoric. These extracts were also felt to illustrate Lyell's characteristic method of geological interpretation and his deeper concerns with the implications of his science, perhaps more clearly than in other published material from the earlier part of his career. At the request of several members of the symposium, I therefore give here a full version of these passages, without the ‘cuts’ and minor alterations that were necessary for the ‘performing script’. The purpose of this paper is simply to make this source-material more accessible, so that it can be used to enrich our understanding of Lyell's approach to geology at this period. I have recently published an account of the circumstances of Lyell's lectures at King's College London in 1832–3 and those at the Royal Institution in 1833, with a summary of their contents, so I shall present these fuller extracts here with the minimum of editorial notes. The two passages chosen are the longest and most continuous of those which Lyell wrote out in full rather than in note form.

There existed between Charles Lyell and Roderick Impey Murchison, the two most prominent British geologists of the mid-nineteenth century, a rivalry that was personal, professional, and theoretical. This rivalry, which was for the most part friendly, was most keenly felt by Murchison, who was always envious of the popular and professional success of Lyell's theories. Although both were born in Scotland and raised in England, where they lived most of their lives, their early lives were considerably different. Murchison's early career as an army officer and fox hunter contrasts rather strongly with Lyell's academic life at Oxford and as a law student. Each was the eldest child of a well-to-do Scottish family. Although Lyell's family was much the wealthier, Murchison personally always had more money than Lyell since Murchison ultimately inherited the estates of his father, father-in-law, and uncle, while Lyell's inheritance waited until his father's death in 1849, at which time the estate was left in trust for the many Lyell children.

‘Non-Progression’, the interpretation of life-history launched by Lyell in 1830 and defended by him for over twenty years, can be summarized as follows. Palaeontologists, Lyell contended, should assume that at every period of the earth's recoverable past, each class of plants and animals has been represented somewhere on earth. Species have been created solely as responses to perpetually shifting environmental conditions, and not as temporally conditioned stages in the unique unrolling of a grand plan. If certain environments are especially suited to reptiles, then the Creator tailors collections of beautifully adapted terrestrial, aquatic, and even aerial reptiles for them—as He did, for example, for the environments recorded in the British Jurassic; as He did, much more recently, for the Galapagos Islands; and as He will do again, if conditions somewhere on earth ever force mammals into extinction, leaving ecological niches which can more suitably be filled by reptiles. If, for example, changes in the topography and climate of the Sussex Weald eventually lead to the re-establishment of an environment that particularly suits iguanodons, then iguanodons will assuredly appear there again. The essential point about Lyell's interpretation is that time does nothing to determine a particular flora and fauna. When designing a new animal, the Creator, according to Lyell's view, has to take into account only the creature's or plant's destined environment: He has to consult no timetable, or lineage, governing the production of new forms. In notes for a speech given in 1852 Lyell reduced his interpretation to the epitome, ‘Adaptation to geographical circumst5 not progressive develop the real history of past changes’.

In the second volume of the Principles of geology Lyell had occasion to speak of G. B. Brocchi, ‘whose untimely death in Egypt’, he said, ‘is deplored by all who have the progress of geology at heart’. Whatever he understood to be the debt of other geologists to that Italian fossil conchologist, Lyell himself owed him much for providing scientific data and interpretations integrated in his own geological synthesis, but especially for furnishing the escutcheon of the third chapter in the review of the history of geology which Lyell appended as a late but enthusiastic embellishment to the Principles of geology. The ‘Discorso sui progressi dello studio della conchiologia fossile in Italia’, an eighty-page essay on the history of his subject, was contained in the first volume of Brocchi's Conchiologia fossile subappennina and afforded Lyell succinct notices on Italian geologists from the sixteenth century to his own time, as well as cues for the introduction of other non-Italian sources.

Lyell's performance as a historian was both fruitful and remarkable. He wrote well; his style was lucid; and he wrote with conviction and authority. In his history of geology we find none of the usual historians’ dodges. No ‘one of the first’, no ‘probablies’, no ‘it would seem that way’. Lyell did not have to resort to such ruses, because he wrote about the truth—the truth, that is, as he saw it. Most of his statements of fact are not incorrect. But in selecting his facts, he left out anything that did not suit his purpose. Other historians of the geological sciences have pointed out the polemical nature of Lyell's history in general. My investigation is limited to a single chapter of his history, Chapter IV of the Principles, and to his treatment of Werner.

In the half century following Cook's entry into the Pacific in 1769, few tropical phenomena excited more attention than coral islands and the corals which evidently built them. In the eighteenth century corals occupied a critical position in the Great Chain of Being. Sometimes interpreted as animals, sometimes as plants, they built large topographic structures of limestone, and thus spanned the gap between the organic and inorganic worlds. ‘The strata which they form are at once living and fossil; we can see them in the act of production, and the mountains grow up to the day before us, new parts of our own earth.’ Towards the end of the century, after Peyssonnel had conclusively shown that corals were animals—variously designated as worms, insects, or molluscous worms—this bridging significance was transferred to the coral islands, new areas of land emerging from the ocean and newly colonized by plants and animals, as an analogue of the primeval earth. This creative process served for some to counterbalance the Huttonian vision of universal degradation: ‘Whatever destroying tendencies … exist on the earth, these renovating powers compensate for them’.

When Charles Lyell was writing his Principles of geology early in 1830, he interpolated five chapters between a recently written historical account of the science and the main body of textual material whose structure had long been determined. These added chapters contained not only Lyell's effort ‘to express the consequences of the uniformity of nature in the history of the earth’, but also his general arguments against the catastro-phic-progressionist interpretation, which he felt obliged to refute. In Chapter IX, the final one in the introductory sections, Lyell chose as representative of the progressionist view, Sir Humphry Davy, ‘a late distinguished writer’ who had ‘advanced some of the weightiest of these objections’ to Lyell's own steady-state view of the earth. No other defender of the progressionist history of the earth was named in Lyell's chapter, and we might well ask, why Humphry Davy? Was he merely an easy target for Lyell's refutations, a straw man set up by Lyell for his own rhetorical convenience?

The development of geology during the first half of the nineteenth century is now considered to be more complicated than was once thought. The positivistic picture of two conflicting schools, one of them allegedly modern and progressive, the other supposedly conservative and scriptural, is too simplistic and misleading. First, the influence of the Bible has been exaggerated. It is true that in the seventeenth and eighteenth centuries the Flood had been given an important role as a geological agent, but in the early nineteenth century there were hardly any professional geologists who defended this view. At least, it is not correct to associate either neptunism, catastrophism, or diluvialism with the Mosaic tradition. Secondly, the use of such terms as ‘catastrophism’ and ‘diluvialism’ has been unfortunate in so far as they have led to biblical associations; these terms must be given a more precise meaning. Thirdly, in the evaluation of the geology of the period, not enough weight has been given to the historical context. From our knowledge of modern geology alone it is not possible to judge what was loose speculation or empirical science at that time. Lyell's contributions to geology, as well as those of his opponents, should be considered and examined in more detail.

The Geological discoveries made during the early nineteenth century resulted in a series of general, predominantly didactic studies, the chief purpose of which was the compilation of large amounts of data. Many of these books were quickly translated from one language into another, and the work of Sir Charles Lyell was, naturally enough, no exception.