dhw: Darwin attributes innovations to random mutations, by which I assume he means that the changes are not purposefully planned by an intelligent mind, but occur by chance.
ROMANSH: Why assume this in theological terms and not scientific terms ... ie these mutations have no particular direction?-There are no assumptions here. Darwin's theory was random mutations, with no particular direction. An alternative to randomness is direction by an intelligent mind: I offered two forms of intelligence: David's God and the intelligence of the organisms themselves.-dhw: I don't have a problem understanding what this means. Whether it is likely or not is a different matter, of course.
ROMANSH: I'm not sure about this ... just remember random does not necessarily mean acausal.-I dealt with this in the passage you have quoted below. together with what I regard as an extremely important point in our understanding of randomness (in bold).-ROMANSH: So when we say something cannot be due to chance are we ruling out cause and effect?
dhw: Not sure about the above, especially since we don't know the causes of quantum events. I'd have thought most of us would argue that all events have a cause and effect, but even though so-called random events have a cause, that doesn't mean they have a plan or purpose, a gap which we often associate with randomness. Fred is walking on the beach and a rock falls on his head. There is a cause for his walking and for the rock falling, but I would say the simultaneity of the combined causes is random (not on purpose), and so the effect is “accidental” (chance/random) death.-ROMANSH: While I would agree we can't see too far beyond the quantum veil (if at all) but here are couple of quotes from The Grand Design that might help us along
QUOTE: Quantum physics might seem to undermine the idea that nature is governed by laws, but that is not the case. Instead it leads us to accept a new form of determinism: Given the state of a system at some time, the laws of nature determine the probabilities of various futures and pasts rather than determining the future and past with certainty.-You seem determined to promote determinism! The above substitutes probability for certainty, which is a massive dilution anyway. Are you now trying to argue that nothing is random because all events are “probable”? This tells us nothing about the nature of randomness. Meanwhile, you have ignored my point that events may be called random because, although we may well know their cause, they are not directed by any purpose or intention.
 
ROMQANSH (quote): “the molecular basis of biology shows that biological processes are governed by the laws of physics and chemistry and therefore are as determined as the orbits of the planets...so it seems that we are no more than biological machines and that free will is just an illusion.-Sorry, but we have debated your views on and definition of free will at least three times, and I'd rather stick to evolution as our reference point. -ROMANSH: Also I object to the blanket use of the word predetermined. This is raising a late eighteenth century straw man. the word determined suffices, or better still caused.-I was quoting from the article you recommended: ”Hard determinists will dispute that subatomic particle behaviour is really random and instead claim that the way they behave is exactly as predetermined as everything else in the universe has been since the Big Bang.” (My bold) Once again, the fact that events have a cause tells us absolutely nothing about the nature of randomness or its relevance to evolution or to the origin of the universe, life and consciousness. Randomness in my view does NOT mean without a cause. It means without a (discernible) plan, aim, intention, prearranged order. That is why I like the definition ”that which cannot be predicted by humans”: we humans cannot discern any plan, aim etc. in actions we call random. But we can usually find a cause, as I illustrated in my example.
 
dhw: An excellent definition, which leaves the whole question wide open. We have no idea what discoveries science might make in a hundred/thousand/ten thousand years, and so currently we can only theorize.-ROMANSH: I too like the definition. So when we say a mutation occurs there is a causal mesh that has caused the mutation that is unpredictable. Or there is an intelligence that has caused the mesh to cause an unpredictable mutation or there is an intelligence that causes the mutation directly (magically in this case). In the last case is the mutation predictable?-In all three scenarios, I doubt very much that any human, had he been studying a bacterium under the microscope 3.8 billion years ago, could have predicted the arrival of the duckbilled platypus, let alone a Romansh and a dhw. In your third hypothesis, only David's God could have predicted the mutation. But we must always bear in mind that what currently seems random or unpredictable to us as humans may not be so in the future, and that there is also a possibility that a superior form of inventive intelligence did have a purpose and guided the mutations. (I am an agnostic).

QUOTE: When it comes down to it, I think the most meaningful definition of randomness is that which cannot be predicted by humans. 
Dhw: An excellent definition, which leaves the whole question wide open. We have no idea what discoveries science might make in a hundred/thousand/ten thousand years, and so currently we can only theorize.-dhw: ...the argument that life and the mechanism for evolution are too complex to have arisen by chance.
ROMANSH: So assuming the you actually agree with the definition of random and assuming for you chance is more or less equivalent to random ... then your position that you must take seriously is this:
... the argument that life and the mechanism for evolution are too complex to be predicted by humans.
But I don't think you mean that predictability is a requirement for evolution.-What I meant is what I said: namely, that I take the complexity argument very seriously because I have difficulty believing that the mechanism for life and evolution could have arisen by chance. The statement could hardly be clearer, so I don't know why you think it needs to be rephrased in terms of prediction. A human cannot predict what is already past, and so “are too complex to be predicted” is quite different from “are too complex to have arisen by chance” Once you start twisting my statement, you can end up arguing that there were no humans around 3.8 billion years ago, therefore the mechanism for life and evolution could not have been predicted by humans, therefore the mechanism for life and evolution must have been random, and therefore there is no God. This, of course, would be a travesty of what I meant.-Initially I liked the above definition because it allows for the fact that human beings might one day in the future discover that what seems random or unpredictable to us now may not seem so then. However, on reflection I will now unreservedly withdraw my enthusiastic support, not only because it opens the path to silly word games (the above is my invention, though - you may have had a different motive), but also because there are events, such as the weather, which I do not regard as being governed by intentionality and which even now are sometimes predicted with a fair degree of accuracy by humans. I will henceforth stick to the conventional definition of “random”: lacking any definite plan, purpose or prearranged order, as in Darwin's concept of ”random mutations”.