Any system of thought requires certain axioms, or presuppositions, which cannot be proven within that system. Last time we saw that science originally rested on a set of presuppositions that arose from the Christian worldview. God is a personal, rational Being. He is the Creator of all things. We were created in his image as personal, rational beings. From this picture emerges the idea that nature is something which can be studied and understood by rational processes without fear of God’s wrath. Natural events can be described and predicted by natural laws which were ordained by the Creator. He pronounced his creation good and commanded us to exercise dominion over it, so he is pleased when we learn to understand and manipulate it.
These ideas about nature have been so thoroughly integrated into Western thought that few are aware of their Christian origins, or that there are other ways to look at the world. But about two hundred years ago a very different presupposition took root in science: everything that happens is presumed to have a purely natural cause which can, in principle, be explained scientifically. In other words, there is no such thing as a miracle. This is called methodological materialism.
It is important to realize that methodological materialism is an assumption. Popular opinion has it that science has proven miracles don’t happen, but the truth is just the opposite: science assumes miracles don’t happen. This assumption is so deeply entrenched among secular scientists today that most would say science is, by definition, the search for purely natural causes of every phenomenon. But this need not be how science is defined, and for most of the history of modern science it was not defined this way. This is not a small matter, because if our assumptions are wrong our conclusions will be wrong.
What is almost always completely overlooked is that methodological materialism is a purely theological concept. It is more a statement about the nature of God than about the nature of the universe. It says that God, if he exists, has never intervened in our world in any significant way. It should be obvious that if there actually is a God who has intervened in nature then methodological materialism will yield the wrong conclusions. The more striking the Divine intervention is, the more striking the error.
I am not saying that methodological materialism is always a bad assumption in every situation. Its applicability is directly proportional to our confidence that God will not somehow intervene and skew the results. In many cases we can be quite confident about that. For instance, even if you believe that God still works miracles to heal the sick, it seems likely this does not occur with sufficient frequency to skew cancer mortality statistics. And in the laboratory, scientists can readily repeat an experiment many times to verify the result, so one can be confident no miracle has occurred.
On the other hand, in the historical sciences such as geology, cosmology and evolutionary biology there is no way to repeat the experiment. We were not there to observe the past events we study. We have only the physical evidence which remains. In this situation the scientist must extrapolate backward using the physical laws we observe today. This extrapolation is based on the assumption that God has not intervened significantly in those events. I believe this assumption is completely unwarranted when extended all the way back to the origin of the world. Naturally, this belief is based on my own theological and philosophical understanding. An atheist would disagree. But that is a religious dispute, not a scientific one, and must be approached as such.
It is clear that science and religion are not separate spheres of human knowledge and thought. In fact, they are inseparably linked. Scientists must make explicit assumptions about religion in order to pursue their study of the natural world. These assumptions are not arbitrary. If they are wrong then the conclusions drawn from them may be profoundly wrong. There will always be a faith perspective implicit in the pursuit of science, especially in the historical sciences.