In the post-World War II Western world, established norms of social behaviour as well as philosophy were being questioned (e.g. existentialism). Into this ferment, R H Blyth launched his four-volume Haiku (1949–1952).
Blyth's interpretations and translations of Japanese haiku are still widely influential on haiku poets writing in the 21st century, whilst his insistence on a very close relationship between haiku and Zen Buddhism is now generally disputed (not least because the Japanese do not accept it). Haiku probably owes more to Shintoism — a refined form of animism.