The animal's mental activity was said to lie in a simple form of thinking, called into being and intensified by means of a certain amount of instruction. Von Osten, who had been a schoolmaster, had previously spent some fourteen years in testing the intelligence of two other horses before he ventured to make his experiences public, and the performances of these animals were not only remarkable, but of far-reaching importance. Hans I, aged twelve, died in 1905. He had never appeared in public, since his abilities had been relatively modest. He had, nevertheless, been able to count up to five, as well as carry out quite a number of verbal instructions. It was Hans II, however, that convinced his master--as early as 1902--of his ability to comprehend a far greater range of the German alphabet (when written), as well as to recognize a certain number of colours. Instances, denoting signs of evident reflection and memory, had led to Wilhelm von Osten turning his thoughts towards this work of animal tuition. Public opinion was divided; there were some who took the subject seriously and who were grateful to this innovator for thus opening a new path of inquiry; yet many were sceptical--and the scientific commission called together in 1904 to investigate the subject, finally knew no better than to heap their ridicule on the careful and patient labours of a lifetime. "Der kluge Hans" ("wise" or "clever Hans")--by that time already a public character--now evoked supercilious smiles and stood disgraced in the eyes of the majority. Only a few, capable of delving more deeply into the subject, continued to follow these performances with ever-increasing interest and amazement and kept their faith whole. Von Osten--though now embittered and pathetically silent--quietly continued his experiments up to his death, which took place in 1909. At first he had gone about his work alone, but he was joined subsequently by Karl Krall, who then became known in connexion with this work for the first time. Many were the attempts made in certain quarters of the Press to account for the facts of the case; the very simple means of procedure employed by von Osten were scouted and the whole thing proclaimed to be based upon trickery, influence, secret signs, an abnormal degree of training, and what not--anything and everything was seized upon in order to come into line with ordinary opinion. Then, in the year 1905, Karl Krall, of Elberfeld, began his experiments with Hans II, encouraging, as a foundation for the furtherance of his theories, the abilities already developed in this horse, while devoting a more profound measure of insight to the entire problem.