Fechner’s work called forth numberless books and articles, confirming, opposing, discussing it, or carrying its conclusions still further. The chief question which they discussed, the question whether the law formulated by Fechner was correct or not, has gradually lost its importance, and made way for other problems. Quite aside from this question, which originally formed the center of interest, Fechner’s work has made itself felt in three different ways. Herbart’s mathematical fiction of the combat among ideas had made such an impression upon the thinkers of the time, that--incredible as it may seem--as late as 1852 Lotze confessed that he would prefer it to formulas found by experiment. For this fiction Fechner substituted a scientific law derived from actual measurement of physical forces. Further, he gave to these facts their proper place in a broad system, showed their significance for the deepest psychological problems, and thus compelled even those psychologists who had affiliated themselves with philosophy and had previously remained unaffected by the physiology of the senses, to take notice of the new movement in their science. And finally, he worked out a methodical procedure for all psychophysical investigations, which was far superior to the methods then employed by psychologists and which continues to be of great use for the study of sensation and perception. At about the same time, in the sixties, psychology received a third kind of impulse. Although weaker than the two just mentioned, it contributed not a little toward increasing the number of psychological problems to which experimental methods could be applied. In the year 1796 the Reverend Nevil Maskelyne, director of the Greenwich observatory, noticed that the transits recorded by his assistant, Kinnebrook, showed a gradually increasing difference from his own, finally amounting to almost a full second. He suspected his assistant of having deviated from the prescribed method of observation, the so-called eye and ear method, and of having substituted some unreliable method of his own. He admonished the young man to return to the correct method and do better in the future. But his admonition was in vain, and he found himself obliged to part with his otherwise satisfactory assistant. Kinnebrook lost his position on account of the deficient psychological knowledge of his time. It was not until two decades later that Bessel discovered that such differences between the results of observations by different individuals were quite general and normal, and that in Kinnebrook’s case they were only unusually great. They depend on the manner of giving attention to both the sound of the pendulum and the sight of the moving star, which naturally differs in different individuals.