In reading Darwin’s Autobiography and his other writings, public and personal, I think a good summary of the evolution of Charles Darwin’s metaphysical/ religious views would be as follows:
Up to 1830- His seminary days he was a Biblical literalist and a big fan of Paley’s arguments. He says in his Autobiography that at this time, “I did not then in the least doubt the strict and literal truth of every word in the Bible.” During his seminary years he developed a love for science and became an Old Earth Creationist.
1831-1836: His Christian faith was “quite orthodox” in his own words when he boarded the HMS Beagle. He was even mocked by the officers of the HMS Beagle for quoting the Bible as an authority on moral issues. The voyage deepened his faith in the Creator as he became an evolutionary creationist. He was still enamoured of Paley’s mechanistic view of the universe with an interventionist God who gave beings their teleology extrinsically the way the modern Intelligent Design movement usually advocates for today.
His final entry of the voyage show he was still deeply theistic:
“Among the scenes which are deeply impressed on my mind, none exceed in sublimity the primeval forests, undefaced by the hand of man, whether those of Brazil where the powers of life are predominant, or those of Tierra del Fuego, where death & decay prevail. Both are temples filled with the varied productions of the God of Nature:— No one can stand unmoved in these solitudes, without feeling that there is more in man than the mere breath of his body”
1836-1839: Darwin rejected Christianity slowly after a period of intense religious reflection during which his prior literalism was shattered on the rocks of the data he had collected. He came to believe there was no difference between the Bible or “the sacred books of the Hindoos” because its history was “manifestly false”, no interventions by God, and a rejection of the dogmas of Christian Faith.
1859: Origin of the Species published. At this time Darwin notes in his Autobiography that his belief in both God and intelligent design “was strong in my mind about the time, as far as I can remember, when I wrote the Origin of Species.”
Darwin clearly believed that biological evolution was teleological. For him, the laws of nature are God’s laws. In an earlier version of the Origin, he explicitly states, “By nature, I mean the laws ordained by God to govern the Universe.”
In the last sentence of The Origin of Species, Darwin gives praise: “There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone on cycling according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”
1860-1861: Second Period of Religious Reflection. His main concern here was whether Intelligent Design was true. This time includes some of his correspondence with Asa Gray to whom he wrote concerning Origin of the Species, ““I had no intention to write atheistically. . . . Certainly I agree with you that my views are not at all necessarily atheistical.” In these letters he also expresses his doubts about ID as being occasioned by the suffering existing in nature as in the wasp which lays eggs in a caterpillar which eventually kills the caterpillar. But then he turns around a sentence later and says there is too much good in nature to dismiss teleology and a Creator.
During this period Darwin in his letters to Asa Gray offers two possible evolutionary interpretations of Intelligent Design:
1. “I am inclined to look at everything as resulting from designed laws, with the details, whether good or bad, left to the working out of what we may call chance.”
Or, 2. “I can see no reason, why a man, or other animal, may not have been aboriginally produced by other laws; and that all these laws may have been expressly designed by an omniscient Creator, who foresaw every future event and consequence.”
1871: The Descent of Man. In this book he still rejects a dysteleological view of evolution although he has become a Deist rather than a Theist.
To those troubled by the thought of man’s evolution from lower forms he gives the analogy of embryology to show that evolution is not so different from the ways we change within the womb.
1876: He writes his Autobiography and gives us his mature metaphysical views over twelve pages called, “Religious Belief”. He gives arguments for and against the existence of God, including in regards to the Problem of Evil. Each is followed by a counterargument. The section ends in a stalemate with Darwin declaring, “I for one must be content to remain an Agnostic.”
Darwin also gives two arguments for and counterarguments concerning Intelligent Design. One is emotional as when we perceive design and it moves us with its grandeur to believe in a Creator (as when Darwin wrote in his last entry on the Beagle above). He rejected such an argument in his Autobiography and says such scenes no longer move him the same way but admits honestly, “It may be truly said that I am like a man who has become colour-blind.”
He then gives a rational argument for teleology/ design in nature as the one he accepts, “Another source of conviction in the existence of God, connected with the reason and not with the feelings, impresses me as having much more weight. This follows from the extreme difficulty or rather impossibility of conceiving this immense and wondrous universe, including man with his capacity of looking backwards and far into futurity, as a result of blind chance or necessity. When thus reflecting I feel compelled to look to a First Cause having an intelligent mind in some degree analogous to that of man; and I deserve to be called a Theist.”
Although he says, “theist” he probably means “deist” in the way we use these words today.
His counterargument to the rational ID argument was to wonder why we should even trust our minds to draw conclusions at all given it has evolved from irrational animals, ““But then arises the horrid doubt— can the mind of man, which has, as I fully believe, been developed from a mind as low as that possessed by the lowest animal, be trusted when it draws such grand conclusions?”
1879-1882: His final years. It is between these two rational arguments he fluctuated throughout his later life between Deism and agnosticism although he came back from his “colour-blindness” to seeing design in nature on an emotional level periodically.
In a letter to John Fordyce he declares, ““It seems to me absurd to doubt that a man may be an ardent Theist and an evolutionist.” Later in the same letter he writes, “In my most extreme fluctuations I have never been an Atheist in the sense of denying the existence of a God.” And, “I think that generally (and more and more so as I grow older) but not always, that an agnostic would be the most correct description of my state of mind.”
It is in the context of his struggles between Deism and Agnosticism at this late stage of his life that we can properly contextualize a conversation the Duke of Argyll relates having had with Darwin,
“In the course of that conversation I said to Dr. Darwin, with reference to some of his own remarkable works on the ‘Fertilization of Orchids’ and upon ‘The Earthworms,’ and various other observations he made of the wonderful contrivances for certain purposes in nature— I said it was impossible to look at these without seeing that they were the effect and the expression of mind. I shall never forget Mr. Darwin’s answer. He looked at me very hard and said, “Well, that often comes over me with overwhelming force; but at other times,” and he shook his head vaguely, adding, “it seems to go away.”