One day, I want to compile a collection of all the metaphors that have shaped modern science. The sciences of the mind, perhaps because we know so little about the mind, have been particularly vulnerable to the lure of facile analogy. There’s the classic “mind-as-computer” metaphor which, although useful, is certainly imperfect. Before computers, the mind was compared to “holograms,” “telephone switchboards” and “hydraulic pumps”. It seems that we can hardly invent a new technology before we feel the need to impose it onto the mysterious workings of the brain.
Of course, every science has its metaphors. String theory has its famous garden hose, electrons whirl in an indeterminate “cloud” and the genetic code is an “alphabet”. It’s easy to pretend that these metaphors aren’t important, and that they don’t shape our scientific concepts and experiments. But that would be naive. Just look at cardiologists, who have been comparing the cardiovascular system to home plumbing for decades:
The plumbing analogy causes serious confusion regarding heart disease, and as a result, we’ve wasted a lot of time and money on cardiac angioplasty that does no good….It turns out there’s a right and wrong place for the plumbing analogy. It’s right for people who have heart attacks that involve a sudden, total blockage of a coronary artery. That’s why procedures to unclog arteries with expandable stents and balloons (“angioplasty”) save lives in emergencies and need to be used more in that setting. But the plumbing analogy fails when applied to stable, partial blockages that don’t lead to sudden heart attacks. And yet doctors can’t let go of the plumbing talk, and they keep unclogging partial blockages. That’s why the vast majority of angioplasties are done for the wrong reasons–that is, for prevention, not acute treatment.
Metaphors are incredibly seductive: they effortlessly slot into the brain, allowing us to make quick sense of difficult ideas. But we should heed Nietzsche’s warning, and always remember that metaphors illuminate as they conceal. If, as Nietzsche put it, our truth is a “mobile army of metaphors,” then it isn’t true. Beware of theories that lean too heavily on analogies.