Here you will find the Poem A Knocker of poet Zbigniew Herbert
There are those who grow gardens in their heads paths lead from their hair to sunny and white cities it's easy for them to write they close their eyes immediately schools of images stream down their foreheads my imagination is a piece of board my sole instrument is a wooden stick I strike the board it answer me yes--yes no--no for others the green bell of a tree the blue bell of water I have a knocker from unprotected gardens I thump on the board and it prompts me with the moralists dry poem yes--yes no--no