Why do biology and geology have to deal with ‘historical questions’ to explain specific events and causal relationships, and why can’t they rely on universal laws, unlike physics?
Biology and other scientific disciplines have problems that are not found in physics. For lack of a better word to describe this problem, let’s call it the historical question. If we were to understand everything about biology, the next question that would arise would be, “Why are there these creatures on Earth?” The theory that partially answers this question is the theory of evolution. Evolution is a very important area of biology, but it’s still an incomplete theory that needs to be refined.
In geology, we want to know not only how mountains are created, but also how the Earth itself was created, and even the origin of the galaxy. These questions ultimately lead to the questions “What is the world made of?” Questions like “How do stars evolve?” and “What were the initial conditions when stars were first created?” are also among the “historical questions” that astronomy addresses. We have learned a great deal about the elements that make up stars and ourselves, and we are gradually gaining a better understanding of the origin of the universe, albeit only a small part of it.
But at this point, physics doesn’t worry much about “historical questions”. The question “Why does this law of physics exist?” is not asked in physics. Once a physicist discovers a physical law, he or she doesn’t struggle with questions like “How did this law come to be?” or “What did previous laws look like?” Of course, there is also the possibility that the laws of physics change over time. If this turns out to be true, then the “historical questions” of physics will evolve into questions about the history of the universe, and physicists will find themselves in the same conversation as astronomers, geologists, biologists, and others.
When a biologist tries to answer a question about a particular event, such as “Why are there no hummingbirds in the Old World?” or “Where did the human species originate?”, he or she cannot rely on universal laws. Biologists must study all the facts relevant to a particular problem and infer various outcomes from the reconstructed set of factors. In the process, the biologist constructs a scenario that explains the facts observed in this particular case. In other words, he constructs a ‘historical narrative’.
This approach is fundamentally different from a causal explanation. Classical philosophers of science based in logic, mathematics, or physics found it difficult to accept this approach. However, recent scholars have made it clear that the classical view is narrow-minded, and have demonstrated that the historical narrative approach is not only valid, but that it is the only scientifically and philosophically plausible way to explain special events.
Of course, this is not to say that historical narratives are “true”. The more complex the system that science encompasses, the more interactions that occur within it. These interactions are often difficult to observe and establish causal relationships. We can only make inferences. These inferences are inherently dependent on the background and experience of the scholar interpreting them, which is why debates often arise over the ‘best’ explanation. Furthermore, all ‘historical narratives’ are disprovable and subject to reexamination at any time.