The series of books entitled The Eternal World Picture contains coloured symbols and their explanations. Vols. 1-4 contain 44 symbols that were either published or prepared for publication during Martinus’ lifetime. Vol. 5 was published in 2012 after Martinus’ death and contains 34 posthumous symbols. Martinus' symbols show invisible spiritual principles and phenomena that are made accessible to our physical senses through the language of symbols. The symbols contain figures, colours and lines, and constitute a kind of “map” of the core cosmic analyses, which Martinus has described in detail in his works. Through these symbols the student is given a visual overview of the elements of Martinus’ world picture, which along with his symbol explanations, provide the reader with a detailed, overall explanation of life and existence.