A verse attributed to the tea master Sen no Rikyū reads: Kiku sahō mamori tsukushite yaburu tomo hanaruru tote mo moto o wasuru na. Keep the rules and forms completely. Even when breaking them, even when leaving them, do not forget the root.
The verse is linked to shuhari, the stages of learning a traditional art. Shu is holding to the basics. Ha is adapting them. Ri is developing one’s own way.