Justified True Belief

What do you believe? How do you know it’s true? What are your reasons for believing it? What even counts as real knowledge?

These are the kinds of questions thinking people ask themselves. I’m sure you’ve asked these questions or ones like them before. We could throw our hands up, shrug our shoulders, and not worry about it. But the questions come back to bite us in the butt if we neglect them too long. These questions are kind of like a mostly good dog. If taken seriously and well-cared for, they will mostly leave you alone. But if you neglect them or treat them poorly . . . “beware of dog.”

There is a theory of knowledge I find really helpful and often teach my students that is called “Justified True Belief” or JTB for short. It goes like this. For something to count as true knowledge, you must believe it for good reasons and it must be true.

All Dogs Are Cats

If you don’t believe something, say you don’t believe the statement “all dogs are cats,” then the claim of that statement cannot be true knowledge for you. You could likely believe the opposite, that all dogs are not cats. And the claim of that statement would indeed be knowledge for you . . . if it is true that all dogs are not cats. Which is indeed thankfully true. Also true: dogs are better than cats (insert hissing sounds). True story.

On the other hand, if you believed that all dogs are cats, like, you believe it in the core of your being, you still wouldn’t have knowledge. Because it is not true that all dogs are cats. Not only must you believe something, the thing itself must be true. But that’s not all. There’s more (insert infomercial background music).

You have to believe things for good reasons. You must be justified in your reasons for believing something. So, for example, you could believe something that turns out to be true. But you might believe it as a lucky guess or believe it for the wrong reasons. I might believe that the moon, to me, often looks yellow. My reasoning for believing it could be a deeper belief that the moon is made out of cheese. My first belief would be true, but my reasons for believing would be faulty. For the belief that the moon often appears yellow to me to fit with the theory of Justified True Belief, I would have to hold that belief for valid reasons.

Here’s another example, on Sunday morning my son Josiah declared that the Kansas City Chiefs would win the Super Bowl. Later that night, in overtime, his claim proved to be true. But did he have true knowledge earlier that day? No. He may have had good reasons to believe they would likely win, but he didn’t really know they were going to win (insert infighting between football fanatics).

You’re a Purple Giraffe

I think this theory proves helpful when we consider how we form our beliefs. We can’t just believe something based on will power. It doesn’t work like that. If someone threatened to harm you unless you believe yourself to be a purple giraffe, you couldn’t truly believe it even if you wanted to more than anything in the world. You could say you believed it, but you would be lying.

So, how do form and keep belief? We tend to believe things when we feel we have good reasons (or justification) for doing so. Those reasons can include trusted authorities, logical arguments, or physical evidence. They can include existential reasons, like a thing feels right or brings joy or fills us with a sense of purpose. Important or fundamental beliefs generally rest upon several different forms of justification. It’s rarely ever just one thing.

While there can be any number of reasons for our beliefs, if we think about them long and hard enough, we should be able to outline some form of justification. But what about when the justification for our beliefs begins to erode? What about when the trusted authorities fail? What about when the logic seems empty or arbitrary? How about when the belief leads to emptiness and despair, when it is said to lead to flourishing?

Protecting Beliefs

You likely have some different beliefs now then you did ten or twenty years ago. If you’re honest, you can likely imagine having different beliefs twenty years from now than what you do today. I always find it interesting to hear how and why people change their views on different important topics. Often it’s the result of various sources of justification for a given belief being dismantled over time. One thing after another seemed not to fit with a particular view.

These things that don’t fit, or support the belief, are called anomalies. When there are too many anomalies related to a belief, when the justification no longer seems justifiable for the particular belief, a person will often explore a new way of making sense of things as an alternative to their former belief. We sometimes use the word paradigm to explain a person’s deeply held belief about the world.

When there are too many anomalies (things that don’t fit) related to their belief system or paradigm, they experience a paradigm shift as they consider new ways of seeing the world. There’s probably a murky middle where a person is holding onto beliefs loosely as they feel the weight of various streams of doubt. Unless there are good defeaters or answers to these doubts and anomalies, then at some point the thin threads supporting the beliefs will snap.

So, what should you do if you want to preserve your beliefs? What if your beliefs seem endangered? Here’s the bad news. You can’t control or protect your beliefs by mere will power. Life doesn’t work like that. And ignoring your doubts about the justification for your beliefs doesn’t work long-term either.

I would encourage you to follow Pascal’s advice to be skeptical about your skepticism. Be willing to doubt your doubts. Don’t move too quickly away from a belief just because one form of justification seems shaky. Your belief could be true, even if some of your reasons are poor. That’s normal.

Deal honestly with your questions and your anomalies. They aren’t going to go away simply by being ignored, denied, or suppressed. They’re like Gremlins. They’ll multiply if don’t deal with them properly. And you certainly don’t want to feed them after midnight (okay, I’ll stop . . . ).

Here’s the thing. If Christianity is true, then belief is ultimately personal. The story of Jesus offers not only historical evidence, but meaning and purpose for our existence. And if he is true, then in the midst of a very uncertain world, we can have real knowledge about what matters most.

Far more than just a theory, Jesus offers answers for some of the most perplexing questions in life. And his life modeled something so beautiful — it’s worthy of contemplation even by the most skeptical of thinkers.