Science & TechMental model
No single water molecule is wet.
Wetness only appears when billions of molecules act together. An ant colony builds roads though no ant knows the plan; a traffic jam arises from perfectly sensible drivers. This is called emergence. Physicist Philip Anderson wrote in 'More Is Different' in 1972: being able to reduce everything to fundamental laws does not mean you can rebuild the universe from them.
Useful: To understand a team, a market or a brain, knowing the parts is not enough.
Source: en.wikipedia.org