How Belief Works is an ongoing series that's best read in sequence, starting here.

We all know what it means to believe something, from the profound – such as the belief that humans are apes – to the mundane – such as the belief that David is vegetarian. Indeed, belief is one of the most basic concepts of human psychology. However, it's also one of those everyday concepts that can be surprisingly difficult to define, like art or happiness.

Belief is a psychological state that involves a claim. In the above examples it's believed that humans are apes and that David is vegetarian.

Indeed, the term belief can refer to either the psychological state or simply the believed claim. That is, it can refer to either believing something or something believed. For example, in the first sense my belief that humans are apes, and someone else's belief that humans are apes, are separate psychological states existing in different heads. But in the second sense they’re the same thing: the believed claim Humans are apes.

So the term profound belief can refer to either belief of a profound claim or a profound claim that's believed – and likewise for the term mundane belief, and the terms true belief and false belief.

However, we often use the term belief by itself to specifically mean a profound claim that's believed, whether moral, political, religious, historical, philosophical or scientific. For example, when we refer to defending our beliefs we're referring to defending particular profound claims that we believe.

The subject of How Belief Works is our belief of any kind of claim, however profound or mundane. Other examples of mundane beliefs are my current beliefs that I’m in my flat, I'm sitting on a chair at my desk, I'm typing these words, it's Tuesday morning, it’s sunny outside, and I went for a hike along a river yesterday.

So what is the definition of belief in the sense of the psychological state? Given that belief involves a claim, it might be thought that the definition of belief is as obvious as it is simple: considering a claim to be true. However, as I’ll explain in the next article, on how beliefs form, this definition is wrong.

Next article: How Beliefs Form – Part 1

How Belief Works