Life and Habit, published 1877. Online.
Butler illustrates for us how significantly non-scientists can contribute to evolutionary theory. ln 1859 when Darwin's "Origin" shattered the last remnant of his Christian faith Butler abandoned training for the clergy. He became first a sheep farmer in New Zealand, then a "Bohemian" painter and writer in London. After starting as a committed Darwinist he came to despise Darwin for failing to credit his grandfather for his evolutionary theories. To Darwin's "Descent of Man" in 1871 he responded in 1877 with "Life and Habit" in which he tried to apply Lamarckism to human evolution.
The book disappointingly trails off without arriving at any alternative theory of human evolution. But along the way Butler has developed several key concepts. He begins by showing how Lamarckism can account for the origin of variation: he illustrates conscious thought leading by degrees to habits, how these can lead to inherited instincts, and these finally can become embodied in new living tissues with new functions. He can't identify the mechanism for Lamarckism but he can make plausible that it happens.
Unlike Darwin though, he's not content for evolution to be defined in terms of behaviors and body parts. What else gets passed down through the generations, Butler asks, and begins a meditation on the meaning of evolution. What's it for? Take chickens--which is more important, the chicken or the egg? What is a chicken but an egg's way of making another egg? Maybe the whole point of chickens is to make possible the evolutionary development of eggs. And having called into question our unconscious identification of the individual adult as the product of evolution he makes the point that personality also is inherited. He ends by picturing our evolution as a the slow development, over aeons, since the dawn of evolution, of personality. Our adult bodies and our repertoire of instincts and behaviors can be seen as merely supports for the slow evolution of personality.
Butler doesn't make the point specifically, but along with personality could go consciousness and volition.
Where is the driver for this process? Butler emphatically plumps for Erasmus Darwin's "living filament" as his term for the agent of evolution, a remarkable fore-fingering of the genome.
That is as far as Butler can go. But it's not a stretch to read into Butler's speculations the idea that the conscious volition each of thinks of as our personal pride and joy is nothing more than a cross section of the genome's own progress in evolving the capacity for conscious volition, for a purpose we may never know.