- Everything is an expression
- Errors are values
- Principle of least surprise
- defaults represent most common cases
- existing conventions and idioms are adopted
- Robustness Principle: be conservative in what you send, liberal in what you accept
- Clarity over brevity.
- There’s one idiomatic way to do it
- Regularity and Orthogonality. Define a small number of concepts and allow them to be combined without restrictions.