Four major tools
I'm just brushing the surface of this beautiful essay (a) by Jamie Brandon.
Here's the hook:
In the history of humanity there have been three major inventions that have enabled people to think in entirely new ways. They allow us to learn more, think bigger thoughts and solve harder problems. They are:
Writing: a means to store knowledge in a brain-independent form that can be easily replicated, transmitted and preserved
Mathematics: a methodology for constructing abstract systems, reasoning about them precisely and finding connections between them
Science: a methodology for finding abstract systems which map closely to the real world
The reason why we teach these in schools to everyone everywhere is that they are part of your cultural inheritance as a human. It is your right to have these tools. Over the last few hundred years they have empowered us to eradicate diseases, light the dark and explore the stars.
Recently there has been a fourth major tool added to the list:
Computing: a way to arrange inanimate systems to simulate arbitrary abstract systems
Jamie's site is awesome, in general. Check out his book notes!