Doubt and ignorance in science

I have heard several people characterize graduate school as: the farther along one progresses in education, the more apparent one’s ignorance becomes. And, generally, I agree – as I learn about the mechanisms behind a particular natural phenomenon, I end up thinking about all the other phenomena and mechanisms of which I am totally unfamiliar.

But it is not just a matter of how much of the world you have been exposed to; I think also that as a scientist progresses, he or she absorbs the notion that it is best to doubt something unless faced with strong evidence to the contrary, preferably experimental. This doesn’t sound radical, but I think it is – the list of assumptions I make about how the natural world works is actually quite long, and the list of phenomena for which I have encountered mechanistic explanations supported by clear, experimental evidence, is really short.

Claude Bernard uses pages and pages to discuss this notion and although he was focused on human medicine, I think the implied principle in his phrase “True science teaches us to doubt, and, in ignorance, to refrain” applies to all science.

The phrase is from An introduction to the study of experimental medicine. Like I said, in this book he is taking a long time (at least according to my 21st-century attention span) to discuss the role of doubt in science, the importance of experimentation, and the critical need to humble oneself in front of nature. In short, he seems to be saying “Get over yourself – nature is complicated so don’t pretend to know it all.”

It seems kind of strange to emphasize that point. It is a point well-taken, as I described above, but today it does not seem necessary to tell scientists that they can’t make up data or tweak it to fit their hypotheses (sure, that does happen, but it is widely understood to be wholly unethical and condemnable). Perhaps it is that in Bernard’s day – the book was published in 1865 – the risk was not an unethical bending of data to fit a preconception, but a mindset that frequently put human wisdom as the pinnacle of truth, rather than clear reasoning supported by strong evidence.