I confess to disliking this argument, for several reasons. First, and most basic, where is the evidence that the universe is "tunable" in the first place? Maybe when we learn a bit more physics we will realise that the constants of Nature have the values they have of necessity, and could not have been otherwise.

For example, suppose I argue that the value of pi must have been very finely tuned, to implement God's high purpose that balls should be round. After all, without that supreme intelligence, cricket would be impossible! The argument is clearly absurd, because we know tthe value of pi is immutable. The fine tuning argument is plausible only because we are ignorant of the physics of the things supposedly tuned.

But my real exasperation is with the statement itself: "The universe is fine tuned for life". If that is so, tell me, where is the life? Where are the worms of Mercury, swimming in molten lead? The dinosaurs of Venus' swampy jungles? The egg-laying Martian princesses - the floating medusae of Jupiter's upper atmosphere - the crystalline cities of Titan? From where I sit, this universe seems almost implacably hostile to life, and we exist, precariously, on the razor's edge of that "almost".

Even here on Earth, 99% of all the species that have ever existed are now extinct. All that labour, all those creatures, those endless forms most beautiful and most wonderful, evolved just to be returned to nothingness. Some tuning! Some tuner!