I <believe> that the title of this article may be a bit of an exaggeration. In this installment I only intend to discuss the literal definition of the word “belief.” But as you will see, that is not as simple as one might imagine. Still, it is an essential first step toward a fuller understanding of belief.

Dictionaries cite a number of distinct definitions for the word belief. It can express trust in a person or a thing, acceptance of a well-known idea, or it can convey our conviction of the truth of a proposition. But those few definitions don’t even begin to touch the wide range of ways the word belief is used in everyday conversation.

The different uses of the words “belief” and “believe” are almost endless. We may say “I believe in forgiveness” to express support for that outlook. We may say “I believe that’s true” to express agreement, or we may say “I find that hard to believe” to express skepticism. We may say “I believe today is Tuesday” to express a factual certainty or “I believe it will rain today” to express a prediction. We may say “I believe I’ll have a piece of cake” to express an intention. We may say “I believe in you” to express trust, or “I believe it will all work out for the best” to express hope.

And yes, we may say “I believe in angels” to express a literal belief in their existence.

It is really only that last usage of belief that makes it a crucial word in the epistemological sense, that is, in discerning facts from lies, reality from fantasy. All those other usages confuse and make it difficult to think about belief clearly in the literal context. So it is important that we understand what a belief is in that narrower context if we are to understand its role in knowing the truth of things.

In this narrow but critical context, a belief is an assertion that an idea is true despite having neither verified facts nor sound logic to support it, particularly when some evidence should be observed if the assertion were true.

Asserting a fact is not, as some like to assert, merely asserting another belief. One does not strictly believe in facts. Facts are supported by logic and evidence. Beliefs, by definition, are not.

Yes, sometimes we may be wrong about a fact. But a mistaken fact is not a belief. While we may be incorrect in our assertion of fact, we did not accept the idea without first concluding that we had sufficient valid evidence to support it.

And yes, sometimes what is a belief at one point later becomes a proven fact. However, that does not make all beliefs some sort of potential facts that deserve provisional respect. A belief is rarely just an unproven fact. That may better be called a hypothesis.

There is another requirement of beliefs that is not normally recognized. A belief must be subject to rejection. After sufficient evidence is presented, the believer must be willing to reject that belief. If they are unable do so, then their belief is actually a delusion. A delusion is a persistent belief that we cling to despite being presented with evidence to the contrary, logic to the contrary, or a lack of evidence where evidence should be found.

So I may hold, what is for me, a belief born of ignorance. But if I continue to hold to that belief after evidence to the contrary has been presented, or after it has been shown that there is no evidence where one should expect to find it, then it becomes for me a delusion.

When we persist in believing an idea despite any evidence to the contrary or a lack of evidence where one expects to find it, then that is no longer a belief, it is a delusion. It turns out that many of the ideas that we commonly call beliefs should by definition be more accurately characterized as delusions.

And one cannot simply rationalize that they are not delusional by refusing to accept evidence to the contrary, by refusing to acknowledge a lack of evidence, or by citing bogus evidence or logic. Our own delusions are not something one can self-assess with any degree of confidence and our rationalizations of our delusions do not make them rational (more on rationalization).

In fact, there is a further category along this spectrum known as a “bizarre delusion.” A bizarre delusion is a delusion that is so extreme, so bizarre, that it deserves a more severe label. A bizarre delusion might be something on the order of believing that one is possessed by a demon.

The number of believers and the level of normalization of a belief do affect how we categorize these ideas. Certainly, for example, belief in God qualifies as a bizarre delusion. But because so many people share this particular bizarre delusion, it seems less bizarre and we upgrade it to a delusion. And because even that would be intolerably insulting to so many people, we further upgrade it to a belief. But belief in God really is a bizarre delusion since it is both exceedingly implausible and not subject to rejection regardless of logical implausibility or a total lack of evidence where one would certainly expect to find it.

Here are some examples of assertions that illustrate these steps along the belief spectrum:

Fact
All life evolved on Earth over the last 3.7 or so billion years (supported by overwhelming evidence).

Mistake
Simple cloth masks can prevent Covid transmission (as stated early in the pandemic but rejected soon after).

Belief
Intelligent aliens must exist but I do not believe they could ever reach us (supported by logic and lack of evidence but subject to reevaluation if evidence is found).

Delusion
The Earth is 6000 years old and evolution is a hoax (stubbornly rejects overwhelming evidence to the contrary).

Bizarre Delusion
I speak to God and he answers me (when meant literally).

I hope this short overview provides a starting point from which to better navigate discussions of belief. You can continue delving into beliefs, how and why we believe them and how to think better, by picking up my new book, Pandemic of Delusion.