Where does belief end and knowledge begin?

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Belief becomes knowledge when there is added to it truth and justification.

The trickiest problem I ever had to fix in a vehicle was an intermittent failure to start. I don’t have perfect knowledge about how my car worked, so I took it to a mechanic, who was completely unable to fix the issue. From him and others I learned that there are three things that will keep a car from starting. Fuel, fire and air. The mechanic was able to rule out fuel and fire, when we changed out the fuel filter and spark plugs.

This left air. The both of us believed that air was the issue, and the mechanic believed that the mass air flow sensor was the culprit. But we replaced it. Twice. I eventually just stopped taking it to him because it was expensive and he wasn’t solving the problem. I suspected it was the giant air intake hose which had developed multiple large cracks and holes over the years. I used a moldable clay ‘glue’ to fix them up but no dice.

Finally I started replacing the mass air flow sensor again. I think I bought three more sensors before the truck would finally start reliably.

A fact is a true belief. My mechanic’s belief that it was the mass air flow sensor became fact when I finally fixed the car by replacing the mass air flow sensor.

People usually conflate facts with knowledge, but they’re not the same thing. You see, my mechanic’s belief didn’t just come from nowhere, it came from an established body of knowledge. This body can be continually added to to form a more consistent grasp of the problem domain that knowledge deals with.

The difference between facts and knowledge is what justifies that a fact is relevant to that problem domain. If you just go to your mechanic to try to tell him how to do his job with a bunch of half-baked ideas, like how lizards are running the world and how chemtrails are keeping us all stupid, the reason he can just ignore you and roll his eyes is that, even if the supposed propositions were true, there’s nothing justifying that they bear relevance to why your car won’t start. Chemtrails don’t affect your spark plugs, or your fuel quality, or whether enough air is getting into your combustion chamber.

It’s not just what, but also how, and why. Knowledge isn’t just a bundle of facts, it’s also a map for how to locate new beliefs on it. My mechanic probably already know that mass air flow sensors on 20 year old Ford Rangers were just really dodgy. What I didn’t realize is that just buying another part doesn’t mean that part is “known good.”

You see, my beliefs in fixing cars were informed by my experience in troubleshooting and fixing computers, and in the consumer computer world, parts coming in from vendors are typically pretty new, 99% of the time, either good or bad. I applied that belief, to that situation, and it produced a situation where I thought I knew more than my mechanic did. It didn’t make sense to me to keep replacing the same part over and over again, but it made perfect sense to him. It didn’t occur to me until much later that almost all the mass air flow sensors out there are comparable in age to the car and will have similar failure rates.

This is what knowledge buys you, a general ability to roam over a problem space and come up with beliefs to test. My experience fixing things was good enough, eventually, to fix the car. But he would have fixed it faster, because he knew cars better than me. But I definitely learned a lot from the experience, to push my own body of knowledge about fixing things forward.

With knowledge, new data points allow you to locate and fill in gaps. Without it, the mind naturally looks for ways to justify relevance. Hucksters and conspiracy theorists make their living by making unjustified connections that look like knowledge, but aren’t. This preys on our psychological weaknesses. You can pretty quickly tell the difference between someone offering real knowledge and a huckster by looking at how they justify their claims. If there’s no real connection and just inferred connections, the intellectual value is going to be very low if not zero.