I read Vestiges of the Natural History of Creation by Robert Chambers for the 1840s installment of the Decades challenge. This is an interesting mixture of wild Victorian aged conjecture about how the natural world works based on the old notions of progress. It was one of Stephen Jay Gould's goals in life to stamp out this kind of idea that the entire history of the world has been leading up to the moment when humans, clearly the pinnacle of evolution, appear. Ya gotta forgive the author for this, as it was the 1840s. It is also necessary to forgive the usual Victorian racism where Caucasians are clearly the most intelligent and advanced of all humanoids. But it appears that all Caucasians who could publish believed that at the time. But, Chambers was ahead of his time. He without a doubt influenced Darwin...a lot I think. Chambers discussed how life clearly went from simple to complex. He discussed the origin of species and how new species come from existing species. He strongly hinted at the tree of life. He recognized how embryology suggests common ancestry. He discusses how existing structures are modified over time. And, most importantly, he breaks the biblical literal interpretation thinking about the natural world.
I think he also influenced the intelligent design folks as well. Chambers clearly believed God was behind it all, but not by micromanaging, but by establishing the laws by which nature will "work". At one point, however, he states: "design presided in the creation of the whole design again implying a designer, another word for a Creator".
I'm glad I read this book. People have discussed in several books I've read the influence this book had on Darwin. Some say a lot. Some say a little. I think it definitely was important. Luckily, Darwin was intelligent and cherry-picked the most accurate observations.