Who said "Nature itself is not fixed, but flows"?

This quote is attributed to Edvard Munch.

Nature itself is not fixed, but flows - Edvard Munch

"Nature itself is not fixed, but flows"

Edvard Munch Nature

Expressionist Painter Norwegian 1863–1944

"I paint myself because I am so often alone and because I am the subject I know best"

"A scream pierces through nature"

"Life begins where fear ends"

"One lonely being screams out across the world"

"Nature teaches us about beauty."

"Nature teaches us patience and wisdom"

"Sometimes it snows in April."

"Every town has a soul, and Twin Peaks has a troubled one."