When Fleck emigrated with his wife to Israel in 1957, where his only son had been living for many years, he was already very ill with cancer and heart problems. For a few years he was employed in the Institute of Biological Research in Ness Ziona. He then wrote in English his last philosophical paper “Crisis in Science. Towards a Free and More Human Science”, that was rejected by several philosophical journals.  Ludwik Fleck died on June 5, 1961, of a second heart attack.