This assumption—that understanding a system’s constituent parts means we also understand the causes within the system—is not limited to the pharmaceutical industry or even to biology. It defines modern science. In general, we believe that the so-called problem of causation can be cured by more information, by our ceaseless accumulation of facts. Scientists refer to this process as reductionism. By breaking down a process, we can see how everything fits together; the complex mystery is distilled into a list of ingredients. And so the question of cholesterol—what is its relationship to heart disease?—becomes a predictable loop of proteins tweaking proteins, acronyms altering one another. Modern medicine is particularly reliant on this approach. Every year, nearly $100 billion is invested in biomedical research in the US, all of it aimed at teasing apart the invisible bits of the body. We assume that these new details will finally reveal the causes of illness, pinning our maladies on small molecules and errant snippets of DNA. Once we find the cause, of course, we can begin working on a cure.
The problem with this assumption, however, is that causes are a strange kind of knowledge. This was first pointed out by David Hume, the 18th-century Scottish philosopher. Hume realized that, although people talk about causes as if they are real facts—tangible things that can be discovered—they’re actually not at all factual. Instead, Hume said, every cause is just a slippery story, a catchy conjecture, a “lively conception produced by habit.” When an apple falls from a tree, the cause is obvious: gravity. Hume’s skeptical insight was that we don’t see gravity—we see only an object tugged toward the earth. We look at X and then at Y, and invent a story about what happened in between. We can measure facts, but a cause is not a fact—it’s a fiction that helps us make sense of facts.
The truth is, our stories about causation are shadowed by all sorts of mental shortcuts. Most of the time, these shortcuts work well enough. They allow us to hit fastballs, discover the law of gravity, and design wondrous technologies. However, when it comes to reasoning about complex systems—say, the human body—these shortcuts go from being slickly efficient to outright misleading.
The essential nature of science is that its truths are subjective. As noted above, the scientific truths that we humans have “discovered” are nothing more than fictions that have not yet been falsified. Scientific truths, then, are not true as much as they are reliable. In essence, the validity of a scientific truth is entirely contingent on one’s ability to use it to predict the future. The “law” of gravity is considered true because one can generally rely on the axiom that what goes up must come down. The same applies to the various “laws” of thermodynamics, “laws” of genetics, and such like.
As such, the fetishism of science is quite problematic, for those who fetishize science generally tend to view science as the ultimate example of objective truth even though scientific truths are actually nothing more than subjective perceptions. This tendency to view pragmatic lies as ultimate truths can lead some to embrace the lies to such an extent that they can no longer believe any truth. Ironically, it is these very people who will claim, quite loudly, that they stand for truth.
See also: “The Limits of Science.”