In the last post, I demonstrated that an unrepeatable original event doesn't disqualify the study of that event from being considered science. It is only necessary for the records of that event to be subject to study in a repeatable manner.
So, is Christianity then a science, despite the non-repeatability of its founding events? Am I saying that repeatability doesn't matter? No; I do acknowledge that an event's repeatability is a desirable quality. Its absence isn't fatal to a scientific study of the evidence for the original event, but of course repeatability would make us more sure of our conclusions. We are certain that atoms exist, because you can image them repeatably in any number of laboratories around the world. This repeatability makes atomic theory more certain.
So, isn't it still regrettable that the historical events of Christianity are not repeatable? This non-repeatability may not be so bad as to warrant dismissal of all evidence, but doesn't it still fall short of the best possible kinds of evidence? Why did God only provide this seemingly sub-par evidence, when so much of science is repeatable? And doesn't this clearly show that science and Christianity are fundamentally different kinds of fields altogether, with no overlap?
Now, I want to be clear that there absolutely is a difference between science and Christianity. Christianity is not a science. However, this difference is not a difference in kind, but in degree. They are both governed by the same rules for evaluating evidence, and the same rules of sound thinking. The SAME rational rule that governs when we can expect repeatable experiments in science also tells us that we should NOT expect repeatable experiments in case of Christianity.
The rule is simply this: you only expect repeatable experiments from the things you can control, things that are "lesser" than you. So in a chemical synthesis, you expect that repeating the experiment will yield the same chemical, because you can control chemicals. The same applies to making a bacterial culture. However, when you start considering experiments on animals, or humans, things do not yet become unrepeatable, but at least more difficult. Human dissections, for example, are more difficult and slightly less repeatable than frog dissections. Ideally, we would raise a group of specimen to have well-developed features which can be clearly identified in a dissection, for pedagogical purposes. This would be tricky with frogs and abominably immoral with humans. Because of this, human dissections compromise repeatability in some small sense, because we often have little control over whether the cadaver was a smoker, or an athlete, or morbidly obese.
We must go on over to the social sciences to consider things that we cannot really control. Once we are no longer dealing with just a dead human body, but a living human mind, we get to psychology. And while it may be interesting to repeat some classic psychological experiments such as the Stanford prison experiment, we cannot ethically do so: we are not permitted to have that much control over our fellow humans, even if they're experimental subjects, and it would be wrong to seek that control.
If we go on to the behavior of groups of humans, no single experimenter can hope for enough control for an experiment. Thus we rarely have sociological or economical experiments in the same way we have physics tabletop experiments. Repeatability of events is not really sought in these fields: we do not, for instance, attempt to re-create the conditions for World War II to study it better. Even suggesting such an experiment would be immoral. Instead we study past events where historical circumstances lined up to create situations that we're interested in.
To bring this back to the physical sciences, consider astronomy: we have no control over when stars go supernova, or how quickly a galaxy moves away from us. To even think that we have this control, in our current technological state, would be pure delusional hubris. That is why repeatability is not sought in astronomical events: the events are beyond us.
I have always liked how, in astronomy, they have 'theorists and observers', instead of 'theorists and experimentalists'. That label of "observers" shows a degree of humility before nature - an understanding that we do not control the heavens, that we cannot perform experiments on it. Astronomers can only observe, and hope for a fortuitous combination of heavenly circumstances to enlighten them.
In all this, the principle is clear and logical; you can demand repeatability of events in subjects you can control, such as chemicals or bacteria. You cannot demand it of subjects that you cannot control, such as human societies or galaxies. Furthermore, this difference is one of the things that separates one type of science from another: for example, the social sciences all deal with things that are hard or impossible to control.
Now, consider Christianity. What is the subject of Christianity? God, and his interactions with humanity. What hope do you have of controlling this subject? None. You cannot control he who controls the heavens. To even suggest it is to incur guilt, in a way that might be glimpsed at by considering the suggestion to trigger another World War. How much repeatability can we then expect from events performed by God? None. We can only observe, like the astronomers observing the heavens.
Notice that the answers concerning Christianity are given according to exactly the same criteria that we use in the sciences. There is one logical principle that gives these answers for both Christianity and science, that allows some scientific events to be repeatable and God's actions to be non-repeatable. What does this mean in categorizing Christianity alongside the sciences? Just as a difference in the subject distinguished social sciences from the physical science, this infinitely greater difference between God and his creation distinguishes Christianity from all sciences - not because Christianity is irrational or handles evidence in a fundamentally different way, but simply because of where it falls in the spectrum of degree of control over the subject.
So, Christianity is not a science. However, this difference is not a difference in kind, but in degree. The same rational rule that governs when we can expect repeatable experiments in science also tells us that we should NOT expect repeatable experiments in case of Christianity. Beneath this difference in degree, they are governed by the same rational rules for handling evidence.
You may next want to read:
The role of evidence in the Christian faith (Conclusion) (Next post of this series)
How physics fits within Christianity (part 2)
Interpreting the Genesis creation story: an introduction
Another post, from the table of contents