In the center stage of this third and last part of the author's treatise about the life and the oeuvre of the German humanist, biochemist, and Nobel Prize Winner Otto MEYERHOF (1884-1951) is the first half of his life. As a young man, in the age of 16 and after a severe renal disease, Otto MEYERHOF spent 1900/1901 five months in Egypt, where he, led by his cousin Max MEYERHOF, Egyptologist and Ophthalmologist, studied the country and its people as well as its architecture and history. During his medical courses he became acquainted with the philosopher Leonard NELSON, who stimulated him to study the Kantian-Friesian philosophy, about which he published several papers. Simultaneously MEYERHOF became seriously interested in GOETHE'S method of natural investigation. About this topic he gave two famous lectures, 1909 in Berlin and 1949 in his American exile in New York. From 1903 MEYERHOF attended medical courses and conducted advanced training courses for workers at the University of Berlin. 1907 in the Heidelberg philosophical circle MEYERHOF became acquainted with Otto WARBURG. 1909 MEYERHOF earned a doctorate in medicine with the thesis "Contributions to a psychological theory of mental disorders". In the years 1911/12 a deep change occurred in MEYERHOF'S scientific career, in the course of which he turned to active experimental research in natural science. However, MEYERHOF remained true to philosophy and his friendship to Leonard NELSON. When Otto MEYERHOF in 1911 obtained a Badian scholarship for experimental research work in the Zoological Station in Naples, a tight collaboration with Otto WARBURG in sea urchin egg biology began. In 1912 MEYERHOF published a famous paper on "The energetics of cellular processes", which became the guideline for his prospective scientific work. In the same year he habilitated at the Medical School of the Kiel University with an enzymological study, and he joined the Physiological Institute of Kiel as unpaid private lecturer. Because of a severe chronic renal disease, which burdened himself from childhood, he became exempted from military service. In the years after 1917 he published several papers on fermentation, glycolysis, and respiration of animal cells and yeast and started after 1918 an extensive experimental project on "Muscle Metabolism and Mechanical Work". In this study he brought together different aspects of muscle metabolism and muscle activity: aerobiosis and anaerobiosis, muscular work, muscular exhaustion, and muscular recovery with glycogen degradation, glycogen synthesis as well as lactic acid formation and lactic acid utilization with muscular oxygen uptake. With this comprehensive experimental approach MEYERHOF in only few years built up a grandiose work about the correlations between muscle metabolism and muscular work. For this brilliant research Otto MEYERHOF and his British colleague Sir Archibald Vivian HILL received the Nobel Prize 1922 for Physiology or Medicine. The two investigators received the honor for their discoveries in the coordination of muscular performance with chemical, physical and thermodynamic processes, MEYERHOF "for his discovery of the fixed relationship between oxygen consumption and lactic acid metabolism in muscle" and HILL "for his research into the quantitative relations between heat production and muscular work". As explicated in the two preceding papers of the author Otto MEYERHOF and his first and longest collaborator Karl LOHMANN from 1925 till 1938 clarified chemically most of the intermediates and enzymatic reactions of the glycolytic pathway, also named Embden-Meyerhof-Pamas-pathway. Because of the antijewish pogrome in Germany MEYERHOF escaped 1938 from Heidelberg and accepted a French offer to continue his research in Paris. But after the German troops occupied France MEYERHOF again had to flee. He, his wife and their youngest son Walter breached through France, Spain to Portugal. From Lisbon he arrived by ship USA.