The great thing about ideas with reach is that you don’t need to learn that many to be set upon the right path.
Here are five ideas with reach, that if you took seriously would allow you to do better than most on lots of stuff:
1) Human minds are universal computers. That means, it’s possible for them to do any computation. That means it’s possible for them to learn anything.
2) Learning is the exact same process as creating. When someone learns from a book, he’s re-creating the knowledge from the book in his own mind.
3) Learning happens by the person making conjectures (guesses) about what a true theory (explanation of something) is, and then criticising it (trying to find flaws in the theory), and then fixing it by conjecturing what might fix the problems. Teachers can only help with this process, not do it for them.
4) In this way, knowledge is evolutionary. Learning is mutation (editing theories) and selection (picking the edits that make it better).
You can also have knowledge without learning, e.g. a species gets more knowledge about how to adapt to its environment by mutation (random changes in genes) and selection (genes that help get themselves copied, survive).
5) In order to learn anything, one must do this process described above. There is no other known process of learning. This means that if an entity can learn one thing, it has the ability to learn anything.
These ideas have consequences. Take (5): this means that we won’t be able to have true ‘intelligent cars’ that learn stuff. By the time we get a car computer that can learn roads and drive for us, it will be able to learn anything, and so would be human. (Note: a car could ‘learn’ stuff if it’s just blindly following a particular program/algorithm. But that’s not really learning, it’s just analysing data according to a code.)
And (5) means that either animals can’t learn, or they’re people (saying they’re people leads to questions like: why haven’t they created anything? why does it look like they can’t learn some things?).
It also means that if children can learn at all, they can learn just as well as an adult can. More precisely: there aren’t special fields of knowledge that children just can’t learn for some reason. Which means that it is not the case that children are unable understand some things (like ‘sense of self as distinct from others’ or ‘future consequences’). They may not have learnt it yet, but there’s no reason to suppose they don’t have the ability to.
It also means that mental illnesses or disabilities do not render people unable to learn specific things. Either they have lost their ability to learn, and can’t learn at all, or they retain their ability to learn, and can learn anything. It’s possible that severe brain damage could cause someone to do this a lot more slowly (or perhaps lose some of the knowledge he once had if the part of his brain where it was kept got damaged), but lack of speed doesn’t mean lack of being able to comprehend.
So, this one idea applies to lots of different fields and issues. It’s not just about computation, or teaching, or whatever — it has wider implications, it reaches to other stuff too. And it has important consequences for the ideas it reaches to: for example, it means it’s possible to persuade a child instead of force them.
What an idea reaches to might not be obvious. You’ll have to learn how to apply it, and work out individual situations. But it’ll be much quicker and involve fewer errors than if you had to work out the conclusions just from the details of the situation. For any given situation, you can check it against the theories with reach.