"There are two qualities in his 'Hand-book of Physiology' which have particularly enhanced my estimation of its value--its strictly philosophical method and its completeness {236} in facts. Since the time of Haller no one has so thoroughly mastered the entire literature of natural history or collected in all directions so many original experiences, and no one has been at the same time familiar with medical practice, as well as with the remotest provinces of zoology. It has been well said that while Haller often, in doubtful questions, espoused a side which must eventually be forced to succumb, Müller always had the luck (if we may call that luck which was preceded by so much intelligent activity), sooner or later, to discern the opinion that was sure, eventually, of the victory. He was wonderfully fitted for the office of critic by his comprehensive knowledge. He knew how to discriminate the healthy from the unsound, the essential or real from the adventitious or accidental. And, in surveying the whole series of forms--often widely different--among which a well-determined plan of nature seemed to be realized, he knew the changes which not infrequently altered considerably the arrangement and composition of the substances within these forms. In Müller, as a physiologist, it is not the genius of the discoverer, nor the ground-breaking nature of his observations we admire, but rather the methodical exactness of investigation in calculating judgment, the confident tranquility and the perfect consummation of his knowledge." In a word, Müller owed the success of his career to the perfect poise of his intellect and the admirable critical faculty that guided him in the thorny path of knowledge at a time when there were so few landmarks of real scientific significance to show the investigator what the probable course and progress of real science must be. It was for this reason that, as Virchow has said, the reform of newer views became embodied in him, and in spite of the almost monastical retirement of the scholar, the influence of the method introduced by Müller was not limited to physiology, but continues to {237} spread beyond that science in ever-widening circles into the domain of all the biological sciences. Virchow concludes: "Müller vanquished mysticism and phantasms in the organic kingdom and he was most distinctly opposed to every dangerous tendency, whether it was pursued under the pretext of physiology or belief, or merely in accordance with conjectures. Müller did not discover, but he firmly established the exact method of investigating natural sciences: Hence, he did not found a school in the sense of dogmas--for he taught none, but only in the sense of methods. The school of natural science which Müller created knew no community of doctrine, but only of facts and still more of methods."