The fine-tuning argument, as far as I can tell, tries to make the case that the universe being the way it is demands an explanation. Or to be more specific, the configuration of the universe has the appearance of design for harbouring life. Of all the possible configurations of the universe, a very tiny fraction could even have life. So the best explanation for the fact that the universe has the appearance of design for life is that it was made by an agency who wanted life.
My suspicions about Grayling's analogy were due to the seeming disconnect between an improbability of a contingent history and the improbability of something with a design-like appearance. In other words, we wouldn't be able to appeal to a contingent history to explain away the design of a watch even if contingent history is a factor in watch-design. So when he says on page 80:
The 'Goldilocks dilemma' of my personal existence, and that of the universe's parameters and laws, is exactly the same thing.I think that Peter S Williams had a fair reason to take exception with it. It doesn't obviously seem like the same thing at all, and requires further justification.
Grayling, however, hits the nail on the head with the final paragraph of the chapter:
We exist because the parameters are as they are; had they been different, we would not be here to know it. The fact that we exist because of how things happen to be with the universe's structure and properties entails nothing about design or purpose. Depending on your point of view, it is just a lucky or unlucky result of how things happen to be. The universe's parameters are not tuned on purpose for us to exist. It is the other way round: we exist because the laws happen to be as they are.It's an important point to make. We necessarily live in a universe that can support us, so if any appeals to fine-tuning are to hold, they would have to show something more - that the universe was made for us. Of course we are going to be a product of whatever the universe can permit, and if the universe was any other way we wouldn't be here, but the same can be said of everything else that exists in a universe of the same configuration. Just as we exist, so do ants, and asteroids, and galaxies, and gamma ray bursts. All of it is a consequence of how the universe is. The fine-tuning view would be that everything else in the universe is a by-product of a universe designed for our purpose - a completely anthropic and unjustified assumption - rather than of us being a consequence of things being as they are.
This is what bothers me about fine-tuning arguments: any reality in which we exist is necessarily able to hold us. If we were made of a different material under a different configuration, the same argument would apply equally well. The reason being is that we are complex entities, dependent on things being as they are for that complexity to emerge. In between the two quotes from the book above was an illustration of this absurdity involving Dr. Pangloss from Voltaire's Candide:
"Observe, for instance, the nose is formed for spectacles, therefore we wear spectacles."We can see the absurdity right there. That the nose holds spectacles doesn't mean the nose is formed for the purpose of wearing spectacles. That the universe harbours human life doesn't mean the universe is formed for the purpose of human life. Even if the universe was purposefully designed so that 13.8 billion years later our species would emerge and God would show himself in Jesus form, the apparent design of the universe doesn't warrant that conclusion. Grayling's book explains why.