Given the task definition and input, reply with output. In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

As a philosopher , Ernst Haeckel wrote " Die Weltra tsel " ( 1895 1899 , " The Riddle of the Universe " , 1901 ) , and " Freedom in Science and Teaching " to support teaching evolution .
As a philosopher , Ernst Haeckel wrote " Die Weltra thsel " ( 1895 1899 ; in English : " The Riddle of the Universe " , 1901 ) , the genesis for the term " world riddle " ( " Weltra tsel " ) ; and " Freedom in Science and Teaching " to support teaching evolution .