The most endearing element of Intelligent Design is that the universe is so fine tuned that only a designer with a purpose could have made it so.
If the structure of the atom was changed just so...If the energy property of the quarks was altered just so slightly...every thing would be different. The Universe as we know it would not exist. And life would not exist.
The Dimensions of the Game
Let's talk about baseball. Many baseball purists think that the game is perfect. It is the perfect team sport and the perfect individual sport. Defense vs. Offense. And if you change the dimensions of the game, it would be different.
Think of it. The bases are 90 ' ft from each other. This accounts for the batting averages being what they are. The majority of baseball players have a batting average between 250 and 275. The really good batters will have an average above 280 and up to 340. Very few if any will have a yearly batting average above 350. In the last 60 years only one player has had an average above 400. It is very hard to get a hit given the dimensions of the game.
Now suppose you changed the dimensions only a little bit. Instead of the base path at 90', you changed them to 89' and 10". That's only two inches. But that would be enough to change the batting averages. Not much but you would affect the close calls. Now instead of missing the close call base hit by 2" you make it by 2". Batting averages would go up from 250 to 275; the outstanding hitters will have averages above 350 to 380.
Changing the dimensions of the game make a change in the game. But it is still baseball. Ohter adjustments may be made to favor the picture. 5 balls will equal a walk; 2 stikes equal a strike out. Change the dimensions to favor the batter, and you change other rules to favor the picture.
But it is still baseball. The game has changed, because the rules have changed. But it is baseball.
The Structure of the Universe
Well that's what the universe is like. If you change the rules so that this universe will produce a set of atoms with a certain atomic structure, you can have different molecular structures that would adjust to the different chemical rules, and hence different physical rules. The table of periodic elements would look different, but you would still have a table of periodic elements.
So the fine tune tinkering would not necessarily be unique. In fact, if you have a universe with the basic laws of F=MA and Shroedingers equation.
You have this universe. Now you can take this universe and change it by tinkering with the rules. But you would get a different universe. However, there is nothing to say that it couldn't evolve life and consciousness. If it did that, if it allowed that, then you would have a universe like ours. It would permit life and consciousness. But it would not be unique.
The Arguement for Design does it show a necessary universe?
The result is that if any universe can create the conditions of life and consciousness, it undermines the argument of design. This is a finely tuned universe, but so is any universe that can create the conditions of life and consciousness. There is nothing special; this is a condition of nature and not necessarily unique. If it is not necessarily unique then the uniqueness factor is not the necessary factor to make you believe in a designer. That is unless you believe that the designer is nature, in the sense that God is nature via Spinosa.
A necessary universe is a unique universe. A universe which can create life and consciousness is necessary only if there is no other way to create those elements; only if life and consciousness can only be created in one universe. If any universe or a great number of possible universes can create life and consciousness then those conditions are ubiquitous; they are pan-universal. So the universe is not unique among universes. It is not unique, and if it is not unique, it is not necessary.