The Overlap of Atheism, Humanism, Skepticism, and Freethought is Limited

Venn diagram
Image by Dominic Flamini from Pixabay

The image at the top of this post shows a Venn diagram depicting the overlap between three common image formats. The content is not relevant, but I wanted you to see one since I was not inclined to create my own. These diagrams are useful for illustrating the degree of overlap between concepts. For example, you might imagine one showing atheism, secular humanism, and skepticism.

To a lesser degree, Venn diagrams can be useful in illustrating the relative size of what they are depicting. They may not be well-suited for this use when the size of what they are depicting varies too much. This is one of the reasons I did not bother to create one to depict what I'd like to talk about here.

Imagine drawing a large circle and labeling it "atheists." If we added another circle representing "secular activists," it would be tiny in comparison. Of all atheists, only a minuscule number are secular activists. Our diagram would be misleading because that circle would have to be so small we'd have trouble seeing it. It would overlap with "atheists" but not completely. It would also overlap with concepts outside of the "atheists" circle. But again, it would be too small to be useful.

For a more interesting comparison, we could keep our circle for "atheists" and add one for "secular humanists." We'd see that this circle would fit inside the "atheists" circle. All secular humanists are atheists. We'd also see that not all atheists were humanists. The "secular humanists" circle would be much smaller than the "atheists" circle, fitting inside it.

We could then add a circle for "skeptics." Most of this circle would fall outside the other two. Many skeptics are neither atheists nor humanists. The "skeptics" circle would have some overlap with the others. Some atheists and humanists are skeptics, but many are not.

We could keep going, adding a circle for "freethinkers" and so on. Our diagram would get messy, and getting the sizes of our circles right would be tricky. For example, I'd guess that our "skeptics" circle would be far larger than the others. Our "freethinkers" circle might be much smaller than the others.

The point is that these various terms are not synonyms. They mean different things. There is some overlap between them, but that varies depending on which ones we focus on. We are wrong to expect that every atheist is a skeptic, secular humanist, or freethinker. We are wrong to expect that every skeptic is an atheist, secular humanist, or freethinker.

These labels can be helpful in understanding what (or how) someone thinks. But they have their limits. Some tell us something; few tell us enough. Remembering this can help us keep our expectations realistic. It can also show us the value of getting to know people instead of assuming we know them when we don't.

For more, see Atheism, Skepticism, Freethought, and Humanism.