What is the difference between science and philosophy? While there are enterprises that are clearly in one or the other, the dividing line isn’t always a sharp one. Science grew out of philosophy, particularly natural philosophy. Some would say that science is itself a type of philosophy. But what is the difference between what we today call science and what we call philosophy?
What is science? As in many broad categories of human endeavor, this is a difficult question to answer. Whole books have been written on the question of what is called, in the philosophy of science, the ‘demarcation problem‘, which is simply another way of approaching the definition. The definition many scientists seem to be the most fond of is Karl Popper’s falsifiability criteria. Popper said that for a notion to be scientific, there has to be a possibility that it could be, or could have been, proven false. In other words, it has to be testable, at least in principle. The falsifiability criteria does seem to have a lot going for it, but it’s reportedly not something most scientists use in their work. It mostly seems to come up when they are talking about pseudoscience (fake science).
I’ve been reading a lot lately about the history of science. After reading about the scientific revolution, the history of astronomy, and of Galileo’s attitudes toward inquiry, I think there is a simpler more primal definition. Science is about reliable knowledge of how reality works, knowledge that allows us to make accurate predictions, and about methods of acquiring that knowledge. What we call today the ‘scientific method’ is actually just a collection of techniques that have proven over time to be the best ways to pursue reliable knowledge. If in the future, better ways are found, scientists by and large will eventually adopt them, albeit almost certainly with a lot of skepticism and caution at first. Indeed, the scientific method has been revised and improved considerably over the centuries.
Note that ‘reliable’ doesn’t mean infallible. Scientific knowledge is never absolute. It is always provisional, subject to being revised or overturned on new evidence. Reliable just means that it is accurate enough to make predictions and perhaps, through technology, manipulate the environment. Science is practical; it is pragmatic; it focuses on what works. Because of this, it has little or nothing to say on questions that can’t be tested.
That’s where philosophy often comes in. Analytic philosophy typically starts with uncontroversial premises, established facts, and extrapolates logically and rationally from there to deduce conclusions about reality. Philosophy can explore topics that science can’t. But by doing so, by going far beyond what empirical investigation can show, it gives up a lot of reliability. Philosophical conclusions can be logically valid but ultimately wrong due to facts we don’t know about yet, or from us not understanding the starting premises as well as we think we do. In other words, philosophical conclusions are, at best, hypotheses. You can’t count on them to build machines, bridges, or rockets. This is most explicitly illustrated by the lack of consensus among philosophers on most philosophical questions.
Scientific equations like E=mc2 or F=ma are reliable knowledge about how nature works. They’re not absolute; Newton’s laws have largely been replaced by Einstein’s as an understanding of gravity, but Newton’s equations remain useful for much of NASA’s calculations. Contrast this with positions on free will, the existence of God, the mind body problem, and the morality of euthanasia, where many people may have confident positions, but those positions don’t have the reliability, the level of consensus, of scientific ones.
What then is the use philosophy? Is it “dead”, as Stephen Hawking opined? The simple fact is, there are many crucial questions where we have to fall back to philosophy, where we can’t, at least currently, get reliable knowledge, where science can’t make determinations. In some areas, like ethics, it probably never will. In these areas, we really have no choice but to reason as best we can. The alternative is to simply fall back on emotion, tradition, or superstition, with all the problems they can bring. It’s also worth noting that what falls within the purview of metaphysics, of philosophy, in one century, could fall within the purview of scientific investigation in future centuries. Philosophy can have an important role in helping us to understand the critical questions. Questions that someday science may be able to seek an answer for.
What can be scientifically established is often frustratingly limited. There are many philosophical conclusions that seem evident, but where the evidence isn’t actually in yet. It’s in these cases where the history of science should serve as a caution on assuming too much. Ptolemy had good philosophical reasons for his geocentric model of the universe, but he made what he probably saw as self-evident assumptions that ultimately gave him the wrong picture. Aristotle thought heavier objects fell faster than lighter ones, a view unchallenged until Galileo experimented on it. For millennia, it was thought that health was a matter of keeping “humors” (blood, yellow bile, black bile, and phlegm) in balance, until modern medical research in the 19th century. When Isaac Newton couldn’t fully account for the solar system’s stability, or why the stars didn’t collapse onto each other, he threw up his hands and said God had to help. Einstein famously couldn’t accept, first a dynamic expanding universe, and later the indeterminacy of quantum mechanics.
This is why it’s important to be aware of the difference between scientific empirical conclusions and philosophical ones. And to be cognizant of the fact that we may not even be aware of the philosophical assumptions that we’re making. It’s also important to understand that science only disproves a notion when it finds conclusive evidence for something else that directly contradicts that notion. (An example is the evidence for geological time scales that contradict young earth creationism.)
Does this mean that we should regard the existence or nonexistence of notions that science can’t find evidence for as equiprobable? Not at all. There is a universe of possible scenarios and the ones some might like to be true are only an infinitesimal slice of those possibilities. We’re on acceptable philosophical ground to be skeptical of notions that have no scientific evidence. But given the limitations of philosophical conclusions, we should hold such skepticism with humility, and an open mind.
- Mach: A Model Of The World Is Not The World (hammeringshield.wordpress.com)
- A Guide to Reality, Part 3 (whereofonecanspeak.com)
- In search of the Scientific Method (pienaarspace.wordpress.com)
- Must we give up understanding to secure knowledge in economics? (3ammagazine.com)
- Philosophy Isn’t All about Arguments (explicitblog.wordpress.com)
- How has philosophy encouraged astronomical research? (aphilosophicalaspect.wordpress.com)
- Pragmatism and Progressivism (limeman.wordpress.com)
- Philosophy of Science Anthologies (fledglingphysicist.com)