This seems obvious, but is often forgotten. When a system functions efficiently, its individual parts are hard to notice. If you want to understand how a system functions, what it is made of, how each part works, but you cannot easily disassemble it and have a look, you have to get out of the nominal regime and let each part function independently, as much as possible.
- To understand subatomic particles in a nucleus, or to figure out the structure of atom, hit them hard with other particles and see what happens.
- To understand free will, focus on the situations where the notion fails.
- To understand consciousness, study altered states.
- To understand mental health, study mental illness.
- To understand anatomy, dissect cadavers.
- To understand logical reasoning, study biases.
- To understand evolution, study artificial selection.
- To understand economics, study market failures.