In the early 21st century, Antony Flew was one of the most respected atheist philosophers in the world. Having spent a lifetime publishing philosophical arguments against theism, and having publically debated highly respected theists such as William Lane Craig, there seemed little chance he would ever change his mind. However, he was also committed to “follow[ing] the argument wherever it leads.” This produced a shift in his thinking over two decades that eventually resulted in him accepting the existence of an “infinite Intelligence”. In his book, There is a God, he briefly summarizes this shift and the reasons behind it, as follows.
I now believe that the universe was brought into existence by an infinite Intelligence. I believe that this universe’s intricate laws manifest what scientists have called the Mind of God. I believe that life and reproduction originate in a divine Source.
Why do I believe this, given that I expounded and defended atheism for more than half a century? The short answer is this: this is the world picture, as I see it, that has emerged from modern science. Science spotlights three dimensions of nature that point to God. The first is the fact that nature obeys laws. The second is the dimension of life, of intelligently organized and purpose-driven beings, which arose from matter. The third is the very existence of nature. But it is not science alone that has guided me. I have also been helped by a renewed study of the classical philosophical arguments…
You might ask how I, a philosopher, could speak to issues treated by scientists. The best way to answer this is with another question. Are we engaging in science or philosophy here? When you study the interaction of physical bodies, for instance, two subatomic particles, you are engaged in science. When you ask how it is that those subatomic particles – or anything physical – could exist and why, you are engaged in philosophy. When you draw philosophical conclusions from scientific data, then you are thinking as a philosopher.
(http://goo.gl/6p6Iep pg. 88,89)