Philosophy and science are both ways of learning about ourselves and about the rest of the world. In this article, we’ll review the two main perspectives on the question of whether and to what degree science and philosophy overlap. This will turn out to show us a lot about what philosophy itself is.
I’ll start with what has historically been the most dominant view of the nature of characteristically philosophical questions. We can call this view ‘metaphilosophical rationalism’; the label isn’t perfect, but it’ll do for now. After looking at this traditional perspective, we’ll move on to a more recent view of what philosophy is: metaphilosophical naturalism.
1. The Traditional View: Metaphilosophical Rationalism
According to metaphilosophical rationalism, most of the characteristically philosophical issues are known about a priori. A priori knowledge is independent of, or prior to, any kind of empirical observation concerning the proposition that is the content of that knowledge. That doesn’t mean that we can know something without making any kind of observation at all; we might have to use our eyes to discover what various colors look like. But some philosophers say that once we have the concepts of red and green, for example, we can know just by thinking that nothing can be all red and all green at the same time (cf. BonJour 1998: 2). You know it just by thinking about it; or just because when you consider the idea of something all red and all green, it just seems impossible; or just because you can’t even begin to imagine such an object.
If we think that characteristically philosophical knowledge is a priori, then this will tell us a lot about the differences between science and philosophy. Here’s a summary of a way we could draw the contrasts:
- Science is about empirical knowledge; philosophy is also about a priori knowledge (if it exists).
- Science is about contingent facts; philosophy is also about necessary truths (if they exist).
- Science is about descriptive facts; philosophy is also about normative truths (if they exist).
- Science is about physical objects; philosophy is also about abstract objects (if they exist).
Okay—that might be a lot of new terminology. We’ll say a lot more about what those mean in other articles. Basically, contingent facts are facts that are the case, but they didn’t have to be; they could have been otherwise. Descriptive facts are about how things actually are, not about how they should or shouldn’t be. Physical objects are—well, that’s not easy to describe. Perhaps they’re objects that are made of matter and have locations in space and time. Abstract objects, if they exist, are somehow not in the physical universe (cf. Plato 1997, bks. V-VII).
Notice the recurrence of the word “also” above. Philosophy is also about empirical knowledge and about contingent, descriptive, and physical facts; it’s just that those are chiefly the focus of science. And notice the recurrence of the parenthetical aside; some philosophers have denied the existence of a priori knowledge (Quine 1961: 43); of necessary truths (Quine 1969: §§ 1-4); of normative truths (cf. Ridge 2013); and of abstract objects (cf. Loux 2006: ch. 2; Armstrong 2002).
Some philosophers think that philosophy comprises three main sub-areas: metaphysics (the nature, structure, and contents of reality), epistemology (the nature and scope of knowledge and evidence), and ethics (good, bad, right, and wrong), generally speaking. If that’s true, then that fits very well with my description above. Metaphysics is largely about necessary truths and abstract objects (Loux 2006). Epistemology is about the arguably normative question of who is justified in believing what, and who knows what (BonJour 2002: ch. 10; Huemer 2002; but contrast Kornblith 2002 and Goldman 1986). And ethics is also arguably normative: it’s about good and bad and right and wrong (cf. Huemer 2005: ch. 4; Ridge 2013).
2. A Newer Perspective: Metaphilosophical Naturalism
The word ‘naturalism’ is used in many ways in philosophy. What we’re talking about here can be called ‘metaphilosophical’ naturalism (Quine 1969; Goldman 1986; Kornblith 2002; cf. Papineau 2013). That just means that this theory is a naturalism about philosophy itself, not merely about some philosophical issue or topic. And the word gives us a clue about what the theory says: it says that there is some strong connection between philosophy and the natural sciences. Most philosophers agree that science can have important things to say about philosophical issues, but some argue that philosophy should largely be replaced by empirical science.
If we accept something like naturalism, then it will be more difficult to define philosophy simply by contrasting it with science. However, we can still identify the areas of ‘science plus philosophy’ that have more in common with traditional philosophical issues: issues that people who call themselves ‘philosophers’ tend to focus on. Where the metaphilosophical rationalist believes that some area of study or thought is characteristically philosophical, the metaphilosophical naturalist can at least agree that historically, it has (as a matter of fact) been associated more with philosophy. Therefore, in my bulleted list above, if we simply replace each occurrence of “philosophy is also about” with ‘traditionally, “philosophy” has been more about,’ we’ll end up with something that nearly everyone philosopher would agree with. Naturalists believe that we should use science to investigate traditionally philosophical questions, but most would admit that their position is relatively new on the scene (Papineau 2013). They will acknowledge that philosophers have normally thought of what they do as primarily pursued through the use of intellect, conceptual investigation, logic, and intuition.
There is substantial debate about whether what have historically been regarded as philosophical issues are ultimately only open to a priori inquiry, or instead more appropriately considered the objects of scientific observation. Indeed, this is one of the most lively and prominent disputes in current philosophy. But we can at least see that the sorts of topics one will study in a philosophy classroom are definable, in general, by contrast with the sorts of topics that the natural sciences study most centrally.
Ridge, Michael. 2013. “Moral Non-Naturalism.” In E. N. Zalta (ed.), The Stanford Encyclopedia of Philosophy, Fall 2013 edition. URL = http://plato.stanford.edu/archives/fall2013/entries/moral-non-naturalism/.
Philosophy by Thomas Metcalf
About the Author
Tom is an assistant professor at Spring Hill College in Mobile, AL. He received his PhD in philosophy from the University of Colorado, Boulder. He specializes in ethics, metaethics, epistemology, and the philosophy of religion. Tom has two cats whose names are Hesperus and Phosphorus. Website: http://shc.academia.edu/ThomasMetcalf