1) the finely-tuned cosmos
There exists in our universe approximately 30 distinct physical and chemical conditions each of which must be finely tuned within very narrow parameters in order for life to develop and prosper. These conditions have been noted by many authors. Those unfamiliar with this line of evidence may wish to reveiw the Wikipedia article on fine tuning here, and further descriptions of the argument here or here.
One such condition involves the synthesis of carbon, a process which takes place inside stars. The renown English astronomer, Fred Hoyle, spent much of his career analyzing the nuclear reactions which have taken place inside stars over the course of the history of our cosmos. It is well understood that these nuclear reactions are responsible for the bountiful supply of carbon in our universe, an element that one might not expect to find in abundance, but which is absolutely essential for carbon-based life. Hoyle discovered that unique characteristics in the nucleus of the carbon atom make it possible for these atoms to be produced in such abundance; he then calculated the likelihood that these characteristics should be present, and learned that they are statistically unlikely in the extreme. He went on to make this oft-cited observation:
“Would you not say to yourself, ‘Some super-calculating intellect must have designed the properties of the carbon atom, otherwise the chance of my finding such an atom through the blind forces of nature would be utterly minuscule.’ Of course you would ... A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.” ("The Universe: Past and Present Reflections." Engineering and Science, November, 1981. p 8-12)Australian biochemist Michael Denton has studied many such elements of fine tuning, and has declared, "All the evidence available in the biological sciences supports the core proposition of traditional natural theology – that the cosmos is a specially designed whole with life and mankind as its fundamental goal and purpose, a whole in which all facets of reality, from the size of galaxies to the thermal capacity of water, have their meaning and explanation in this central fact." (Nature’s Destiny, p. 389).
While many of these evidences of fine tuning will be studied for many years to come, and we may find natural explanations for some, I am convinced that most will continue to point back to Holye’s “superintellect”, and Denton’s “special designer”. But not conclusively; it should be noted that other explanations have been suggested which might account for fine tuning. The most common of these are various multiverse scenarios. We are told that perhaps ours is just one in a chain of billions or trillions of universes; if so, the chances that one such universe would result in conditions favorable to life ultimately rise to one in one; and voilà, here we are!
Thus, the arguments from fine-tuning, no matter how intuitively they point to a Creator, can never prove the existence of God. For me and many others, however, Occam’s razor (the logical construct which says, “All other things being equal, the simplest solution is the best”) leads us to a strong likelihood of a “superintellect” First Cause. The alternate explanations, while plausible, are complex and lack evidence. It is my view that the simplest solution is to credit fine tuning to the hand of the Designer, Planner, and Creator of the universe.
It is interesting to note that fine tuning, which may be the best of all theistic arguments, is rarely invoked by Creationists, even by Intelligent Design proponents like Philip Johnson and Michael Behe. The reason is that the fine tuning argument presumes naturalistic evolution. Fine tuning thus works bests for those theists who fully embrace Darwinism, as I do. And for me, an intelligent Creator is the simplest, most intuitive, and thus most likely explanation of the life-friendly cosmos in which we find ourselves.