Adopting the pseudonym of Yonatan Ratosh, he began to write poetry that "tore apart" (Hebrew: -
riṭṭêš) existing conventions of style, language, and culture. In 1939, he founded the Canaanite movement, which rejected both religion and Jewish nationalism. This group promoted the theory of a shared cultural heritage for the entire Middle East. The literary output of the movement was strongly influenced by an ancient, pre-biblical mythology and vocabulary. Ratosh's own work is closely linked to the movement's political theory. His early poems are very structured, and play with rhyme and repetition to create an almost hypnotic effect. His later work employs colloquial diction and more contemporary style. While the movement founded by Ratosh was never broad, T. Carmi wrote that "its emphasis on myth and its stylistic mannerisms had considerable impact on contemporary poetry." In an essay entitled "''Ketav el ha-No'ar ha-'Ivri''" (, "Epistle to the Hebrew Youth") from 1943, Heilperin/Ratosh presented his new ideas to the Hebrew-speaking public. This and other essays called for the community of the
Yishuv to divorce themselves from their Jewish roots and embrace a new identity as "Hebrews". The "Young Hebrews" became known as the Canaanites, a mocking name coined by Haaretz editor
Avraham Shlonsky. In 1950, Ratosh founded and co-edited the literary journal
Alef which published translations of the work of
Stendhal,
Camus,
Shaw and
O'Neill. Ratosh continued publishing poetry and enjoyed a brief renaissance as an ideologue after the
Six-Day War. His political philosophy had an impact across the political spectrum: sharing the Right's
irredentism and advocating a secular (in lieu of Jewish) state like
post-Zionists, particularly radical peace advocate
Uri Avnery. His last poem in book form was
Hava ("Eve"), published in 1963. In it, he reinterprets the story of the
Garden of Eden as the coronation of a Rain God. ==Hebrew science fiction==