model of interpretation for the succession of life on earth. Lyell, aware of how 
Davy's opinions weighed with his contemporaries, criticized this scientist's 
views in chapter IX of the first volume of the Principles.
 

Davy was aware of the possible materialistic uses of a progressionist model. 
Philalethes, in the fourth dialogue, strongly attacked the progressionist 
interpretation of the development of the nervous system on the grounds of its 
atheistical overtones. In an implicit reference to the lectures delivered by 
William Lawrence at the Royal College of Surgeons, and published in 1819, 
Philalethes remarked :
 

When I heard with disgust, in the dissecting room, the plan of the physiologist, 
of the gradual accretion of matter, and its becoming endowed with irritability, 
ripening into sensibility, and acquiring such organs as were necessary, by its 
own inherent forces, and at last rising into intellectual existence, a walk into 
the green fields or woods by the banks of rivers brought back my feelings from 
Nature to God (18).
 

Lyell was not insensible to the writings of the political economists, and to the 
general cultural climate in which more and more stress was put on the 
possibility (and ideological necessity) of explaining natural phenomena in terms 
of ‘secondary causes’, or necessary laws ; he was not, therefore, sympathetic 
towards an approach which tended to place more than the due emphasis on the 
providential element in the government of nature. But nor was he willing to 
accept a scientific hypothesis which explicitly favoured materialistic 
conclusions. He thought that it was possible to implement a fully scientific 
approach to the natural sciences without affronting the prejudices of the age 
and his own beliefs. We shall see how he was convinced that he had elaborated an 
acceptable natural explanation of the succession of species through geological 
epochs, and how at the same time he thought he had avoided any link with 
Lamarck, presenting himself as the definitive critic of transformism.
 

Another event which can help our understanding of Lyell's attitude towards 
Lamarck was the publication in 1826 of J. C. Prichard's (1786-1848) second 
edition of his Researches into the physical history of mankind (19). Prichard, 
following Ray, Buffon and Blumenbach, defined species as groups of individuals 
which could interbreed, and produce offspring capable of perpetuating their 
type. Species modified themselves into varieties according to differences of 
circumstances, although the extent of the variability was thought to be very 
limited. Prichard also doubted whether such variations could be explained in 
terms of the direct action of the environment. The physiological character of 
species, the possibility of procreation, never altered. Prichard admitted that 
several species exhibited an impressive number of morphological varieties, as in 
the case of the dog, of the horse, and of man himself. But no degree of 
diversity placed in question the unity of these different varieties, or of their 
being only morphological modifications of the same species. 

(18) Ibid., p. 219.

(19) J. C. Prichard, Researches into the physical history of mankind, 2nd edn., 
London 1826, i, 97 ; quoted by Lyell, Principles, ii, 52. For a brief but 
substantially correct assessment of Prichard's position in the anthropological 
debates of the early nineteenth century, see W. F. Bynum, ‘The great chain of 
being’, History of science, 1975, 13, 13 and passim. For a more complete 
consideration of Lyell's debts to Prichard's work, see F. N. Egerton, ‘Studies 
in animal population from Lamarck to Darwin’, Journal of the history of biology, 
1968, I, 225-59