Lyell's contribution to Darwin's thought processes had more to do with geology (especially the tempo of geologic change) than with biology. What Darwin absorbed from Lyell's work (he read Lyell's Principles of Geology while aboard the Beagle) was the idea that small changes, if they accumulate over a long enough span of time, can produce huge results. (John Passmore sums it up as: "Great effects need not have great causes.") Lyell made this idea the basis of his (revolutionary) understanding of the history of the Earth. Darwin applied it, post-voyage, to the history of life.
Lyell himself, for all that his work was essential to Darwin's, had deep reservations about evolution . . . largely because he feared that any theory of evolution would eventually expand to include humans (a prospect that horrified him because, Lyell believed, it would rob humans of their uniqueness and thus their dignity).
Lyell eventually accepted, grudgingly, the ideas laid out in Origin of Species and endorsed them in the first post-1859 edition of his own Principles of Geology. He never did come to terms with an purely evolutionary orgin for Homo sapiens, though (to the great annoyance of Darwin, Huxley, and other evolutionists).
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Lyell himself, for all that his work was essential to Darwin's, had deep reservations about evolution . . . largely because he feared that any theory of evolution would eventually expand to include humans (a prospect that horrified him because, Lyell believed, it would rob humans of their uniqueness and thus their dignity).
Lyell eventually accepted, grudgingly, the ideas laid out in Origin of Species and endorsed them in the first post-1859 edition of his own Principles of Geology. He never did come to terms with an purely evolutionary orgin for Homo sapiens, though (to the great annoyance of Darwin, Huxley, and other evolutionists).