Like the two boats in the picture, there are two types of truth. Two brothers, same, but different.
One is true only when enough people believe it’s true. Other is true regardless who believes it’s true.
It’s important to recognize which one you’re dealing with.
When I ask people for me examples of each type, common example they give me for the first is whether God exists or not. Sigh. Regardless of whether you believe in God or not, the belief doesn’t create it. It existed or didn’t exist before you believed or didn’t believe. So God is not a good example for the first type.
So what’s a good example for the first type, a truth that’s only true if enough people believe in it?
Value. Of anything, really, but let’s take money for instance. Money is a number on the paper or bits in the computer. The only thing that allows you to exchange it for other goods with people you don’t know is that they believe they’ll be able to exchange it for something else from someone else they don’t know. If enough people stopped believing in its value, it would no longer have value.
Other societal constructs often also fall into this type.
Evidence based, reproducible, non-anecdotal things are the second type.
2 + 2 = 2 * 2
Gravity attracts matter.
When you push things hard enough they move.
Other sciency stuff.