What, if any, is the difference between religion and philosophy?

Turns out there is one, but it’s not what you may think

Left: Christ Pantocrator of St. Catherine’s Monastery at Sinai, Egypt, 6th century CE; center: The Buddha, Tapa Shotor monastery in Hadda, Afghanistan, 2nd century CE; Right: Zeno of Citium, bust in the Farnese collection, Naples, Italy. Wikimedia.

I am a philosopher. And I am not a religious person. These two sentences imply that philosophy is distinct from religion, and yet many would object, including a number of philosophers. I’ve given this issue much thought and have arrived at the conclusion that there is, indeed, a continuity, but also at least one fundamental difference between the two. And that difference has—perhaps surprisingly—nothing to do with gods.

For the purposes of this discussion, let us compare three religions/philosophies: Christianity, Buddhism, and Stoicism. I picked these three because most people would agree that Christianity is clearly a religion, that just as clearly Stoicism is a philosophy, and that Buddhism falls somewhere in between. However, nothing important hinges on my specific choice, and the reader is welcome to repeat the exercise by swapping one or more of the candidates in this list for other examples of religions/philosophies.

In the introduction to a book that I co-edited with my colleagues Skye Cleary and Dan Kauffman, How to Live a Good Life—A Guide to Choosing Your Personal Philosophy of Life, I suggested that both religions and philosophies have three common elements: a metaphysics (i.e., an account of how the world hangs together), an ethics (i.e., an account of how we should behave in the world), and a set of practices. The following table should make clear what I mean, though the entries within each cell are meant to be illustrative, not exhaustive: