In a controversial interview, Neil deGrasse Tyson dismissed philosophy as “distracting.” The host of the television series Cosmos even suggested that philosophy could inhibit scientific progress by encouraging “a little too much question asking.” He thus follows a growing secular trend that cordons Science off from all other forms of inquiry, denigrating whatever falls outside science’s purported boundaries – especially the more “speculative” pursuits such as philosophy.
Fortunately for the progress of science, Albert Einstein didn’t take this attitude. According to him, studying the “history and philosophy of science” provides an “independence” from generational “prejudices” necessary for creative thought. Moreover, the “independence created by philosophical insight is,” Einstein thought, “the mark of distinction between a mere artisan or specialist and a real seeker after truth.” By enabling one to see the “forest” rather than the “trees,” a philosophical understanding of scientific history is indispensable for understanding -- and even practicing -- science.
Start with history: science grew out of philosophy. As deGrasse Tyson himself notes in the interview, physics used to be called “natural philosophy.” The word ‘physics’ comes from the Greek, ‘physis’ which means ‘nature.’ Physics, accordingly, was the rational and systematic, namely, philosophical, study of nature, the aim of which was what the Greeks called 'episteme,' or, in Latin, 'scientia,' meaning ‘knowledge.’
The way we use the word ‘science’ and its derivatives doesn’t always reflect this etymology. In English, a scientist isn't one who has knowledge so much as a practitioner of a branch of the natural sciences. Similarly, to be ‘scientific’ is not to be systematic or rational -- as the Latin term would have implied to classical or medieval authors -- but to be amenable to experiment. This is why the human and social sciences are thought of as ‘soft’ by comparison, their scientific credentials a matter of dispute (if not condescension), and why their practitioners are typically not referred to as ‘scientists.’
In French, by contrast, while the word for science shares the same Latin root, scientists are known as ‘savants,’ or those who have knowledge. (The cognate ‘scientiste,’ interestingly, means someone guilty of scientism, or thinking that all knowledge is narrowly scientific). In German, similarly, the word for science -- Wissenschaft, literally ‘knowledge-hood’ – is much broader than in English, applying equally to the natural and the human sciences.
Contemporary emphasis on the practical applications of the natural sciences tends to obscure the fact that while the scientific method is 'practical,' in so far as it is experimental and relies on high-tech tools, its results are not. The value of scientific knowledge stems, first and foremost, from the fact that it explains the world -- that it is philosophical. It is almost heretical to say as much, but it shouldn’t be.
Consider the topic of deGrasse Tyson’s T.V. show: how useful is it -- really -- to know that the universe began with the Big Bang, that the Earth orbits the sun, or that the seasons are caused by the tilt of the Earth on its axis? These things may be useful for certain pursuits (astronomy, meteorology). But it’s useful for a student or teacher of philosophy to know the difference between dualism and monism or for a historian of 20th century Europe to know about the Zimmerman telegram. Stellar spectroscopy doesn’t help the layman pay the bills, pick the kids up from school, or lead a moral life.
Modern technology, from nuclear energy to integrated circuits, may be indirect results of liberal arts such as physics. But they are the direct results of what used to be called the “mechanical arts”: engineering and applied sciences. Nor are the natural sciences the only liberal arts with practical implications. John Locke’s Treatise on Government, Montesquieu’s Spirit of Laws, Rousseau’s Social Contract, and Marx’s Communist Manifesto were hardly idle musings. The revolutions of 1776, 1789, 1848, and 1917 changed the world a whole lot more than the invention of the iPhone.
None of this suggests that scientific knowledge is unimportant or lacks practical implications. But scientists in our own day surreptitiously bask in the glow of modern technological advances. The real contribution of the natural sciences is, like philosophy, knowledge, not utility (though the latter may be its byproduct).
Not that science and philosophy are indistinguishable. On the contrary, since natural philosophy broke away from the rest of philosophy sometime in early modern period, a division of labor has been established between the two forms of inquiry. And this was a good thing.
But the division of labor is not that philosophy is speculative while physics is not; rather, each discipline looks for different kinds of answers. Modern physics can ask speculative questions such as, “When did the universe begin?” or more practical questions such as, “How can we infer the existence of a planet by observing gravitational effects?” In either case, the answers depend on empirical and experimental evidence.
Modern philosophy, by contrast, asks questions such as, “What does it mean to accept the truth of a scientific theory?” Crucially, philosophical answers rely on different forms of evidence: not observations, but sound reasoning. A philosophy of science isn’t a theory alongside scientific theories, but a framework for evaluating such theories.
DeGrasse Tyson is right that such questions are not usually germane to the working scientist. But that doesn’t render them superfluous or counterproductive. Scientific progress not only requires the day-to-day work of “practitioners,” but also those who see the proverbial forest. Revolutionary thinkers break out of accepted paradigms and question received wisdom; they engage in precisely the kind “question-asking” for which deGrasse Tyson would banish philosophy.
Helmholtz, Mach, Planck, Duhem, Poincaré, Bohr, and Heisenberg are a few noteworthy modern scientists “distracted” enough to engage in philosophical question-asking. Einstein himself read philosophy voraciously beginning from an early age (he read Kant when he was 13) and engaged in lively disputes with many leading philosophers of the era. Mach’s empiricism, Poincaré’s conventionalism, and Duhem’s holism all influenced Einstein’s thinking. Such cross-pollination between philosophy and science did not stall the progress of physics, but instead led to one of the greatest scientific revolutions in history.
According to deGrasse Tyson, while philosophy used to contribute “materially” to the physical sciences, this hasn’t been the case since the early 20th century. This is ironic. We still live in the wake of the revolution wrought by relativistic and quantum physics and, as Lee Smolin has argued, there have been surprisingly few fundamental advances in our most basic physics in decades. Modern physics has long benefited from a strong, if ambivalent, relationship with philosophy. Severing that tie comes at a price. We may already be paying it. It’s time for scientists to start asking philosophical questions once again.