A friend of mine told me that she’s been archive binging my blog, but complained about me using words she doesn’t know, particularly “naturalism.” This is a bit embarrassing to me as a writer, because I thought I’d been clear on this point, but then we all overestimate how clear we’re being. So let me tale a moment to say that “naturalism” has a bunch of definitions.
In fact, the very first sentence of the Stanford Encyclopedia of Philosophy article “Naturalism” states: “The term ‘naturalism’ has no very precise meaning in contemporary philosophy.” It goes on to say that “is not a particularly informative term as applied to contemporary philosophers” and that it would be “fruitless” to try to pin down a more precise definition.
I most often encounter the term “naturalism” as something religious apologists attack because they wrongly imagine that if they can knock down one alternative to their religious beliefs, they’ll have proven their religious beliefs to be true. And often, their definition of naturalism is a complete strawman, having little basis in what people who call themselves “naturalists” actually believe. Graham Oppy’s review of Craig and Moreland’s Naturalism gives an especially egregious example of this.
A more sensible definition of “naturalism” given by a religious apologist comes from Alvin Plantinga’s Where the Conflict Really Lies. He writes: “I take naturalism to be the thought that there is no such person as God, or anything like God.” That’s similar to my own preferred definition of the belief that ”there aren’t any gods, the miracles claimed by the world’s various religions didn’t happen, there isn’t an afterlife, magic spells don’t work, and so on.” But when it comes time to critique naturalism, Plantinga re-introduces the standard fallacy by declaring he’ll take naturalism to include materialism.
And these are cases where theists have given a definition of naturalism. Often, they don’t give a definition and just start asserting horrible consequences of naturalism willy-nilly.
Admittedly, part of the reason that I think first of religious apologetics when I hear the word “naturalism” is because I’m not personally very attached to the term. But many atheists are. So while writing this post, I went out to grab a few definitions of “naturalism” from around the web, and was somewhat surprised to find that the definitions tended to be pretty similar to my minimalist one.
For example, Internet Infidels (which was one of my introductions to atheism on the web) describes itself as, “dedicated to promoting and defending a naturalistic worldview,” citing Paul Draper’s definition of naturalism as, naturalism as “the hypothesis that the natural world is a closed system, which means that nothing that is not a part of the natural world affects it… naturalism implies that there are no supernatural entities.”
Or, Tom Clark, of the Center for Naturalism, writes: “If you don’t believe in anything supernatural – gods, ghosts, immaterial souls and spirits – then you subscribe to naturalism, the idea that nature is all there is.”
Luke Muehlhauser, who used to blog at and is now the direct of the Machine Intelligence Research Institute, also has a website called Worldview Naturalism, which also has a short video intro to naturalism, which gives a somewhat more detailed definition of naturalism, but which is still mostly pretty minimal.
Of course, some self-described naturalists do advocate stronger definitions of naturalism. A focus on excluding “supernatural” entities is still common, but that may be spelled out in ways that reference whether something is spatially located, or irreducibly mental. The claim that “everything is natural” can also be taken to rule out not just gods and spirits, but also, say, views of mathematics that describe mathematical entities as being somehow separate from the natural world. (Keith Augustine has some discussion of this last way of defining naturalism here.)
There’s also “methodological naturalism,” the use of naturalism as a working assumption under the scientific method. “Methodological naturalism” is sometimes invoked to claim science can’t say anything about the supernatural. I disagree with that, on the other hand, if the point of methodological naturalism is that we should assume naturalism because science has never found a supernatural hypothesis to be correct in the past (even though it could have), I’m on board with methodological naturalism.
Finally, in philosophy there’s a broader methodological view sometimes called “naturalism” which is taken to be about the relationship between science and philosophy. In the words of Brian Liter, it’s “the idea that questions about what there is and what we can know are basically scientific questions, rather than distinctively philosophical questions.” Though this is a definition of naturalism I hear relatively infrequentky,