Added to this pedantry was an extraordinary uncritical attitude of mind, induced by his obsession by one favorite idea, which blinded him to all objections. He met objectionable observations on the part of others in one of two ways. One method was by attributing to Hans certain remarkable qualities, such as an extraordinary keenness of hearing and a wonderful power of memory, or again, certain defects, such as moodiness and stubbornness,--which as a matter of fact, were only so many back-doors by which he might escape from the necessity of offering adequate explanations. When Hans was able to give off-hand a gentleman's name which he had heard years before, it was called a case of extraordinary memory. When the horse insisted that 2 times 2 was 5, he maintained that it was an example of animal stubbornness. There was still a simpler method of overcoming inconvenient objections and that was by ignoring them altogether. The number 1, the simplest and most fundamental in the system of numbers, was one of the most difficult for Hans. (Page 67f.). Mr. von Osten was aware of this, but thought little of it. During the very first visit of Professor Stumpf, Mr. von Osten asked the horse: "By how much must you increase the numerator of the fraction 7/8, in order to get a whole number?" Hans repeatedly answered incorrectly and always tapped numbers that were too great. The same question was then asked concerning the fraction 5/8, and immediately there was a correct response, (the favorite number 3). Mr. von Osten said very naively: "In the case of the difference of 1, he always goes wrong. It was just what I expected." Mr. von Osten still relates that the distinction between right and left created far greater difficulty for Hans than all of the work in fractions, and that even to-day it is not thoroughly established; also, that the selection of colored cloths is often a failure still, although it was one of the first things in which he was given instruction. It appears never to have dawned upon Mr. von Osten that the arts in which Hans seemed to excel, also formed the standing repertoire of so many trained horses, regarding whom it was well-known that they owed all of their cleverness to the training given them by their masters. This fact alone should have induced him to make some form of critical investigation.