He and Beuys shared similar views on Humanism , social philosophy , ecology and libertarianism .
In 1981 , he used an appearance at the Kassel Documenta 7 exposition to dye the Rhine , and joined German artist Joseph Beuys in planting 7,000 oaks .
He and artist shared similar views on Humanism , social philosophy , ecology and libertarianism .
In 1981 , he used an appearance at the Kassel Documenta 7 exposition to dye the Rhine , and joined German artist Joseph Beuys in planting 7,000 oaks .