| padib said: After bold. (I read some before the bold but the after bold part is what I find interesting I can better contribute to) The logic goes something like this: assuming the universe is by design (which it is but that's another story), if the universe was meant for human existence (which it also is, but whatevs), then we should find in the universe hints of design suited for human's survival, or that the sustenance of human existence hinges on very precise calibration of the human's environment parameters and that would be solid evidence for the idea. If those are not found, then it should be evidence against the universe being designed to nurture human existence, and thus being designed for humanity. |
Ok, but the thing is that if you don't presuppose humans to be special than the idea of a fine-tuned world loses meaning if other kinds of life-forms could have surfaced instead given different conditions. The other explanation, though, that humans just happen to be what came to thrive under these conditions, and are thus molded by these very conditions, remains very much plausible.
So for this kind of argument to work you have start out by supposing "humans are special". By doing so the conclusion you reach is "the world is fine-tuned for humans", and then one might try to say, from this, that the universe was thus designed to nurture us, since there's this fine-tuning. But this is the same as saying "if humans are special than humans are special".
The bolded part though shows all that could actually try to be inferred about from this: consistency (or negation). As in, supposing it's right won't bring about a logical contradiction or contradiction with the evidence on this given aspect. It could never, however, in any way, be used to try and prove that intelligent design is right, which is what he initially implied (or at least I understood it this way), because the argument would essentially end up begging the question.
Do notice taht saying "humans are not special thus there's no fine-tuning" faces the same adversity. So, focusing only on this very specific arguemnt, both remain equally sound but unprovable. But so is also the case with the idea that the world is fine0tuned for ants or bacteria or whatever. Faced with both possibilities the simpler one seems to me to be the one that involves less "special cases", ie, the one that says the existing species are just a product of their enviroment's condition, and thus "fine-tuned" to it.
As a side note, one might argue the world is not quite as perfect for us as it might be.
