the principle of fluidity and immutability in haiku; the interchange between the transient and the immutable
A yojijukugo central to Bashō's haiku philosophy, expressing that haiku must balance the unchanging (不易) with the ever-changing (流行). Used in literary and aesthetic contexts.
Bashō considered the principle of fluidity and immutability fundamental to haiku.
The concept of 不易流行 advocates a balance between tradition and innovation.