Such is the somewhat obscure account given of the tetrad.[282] It was intended clearly for pankratiasts and boxers who practically formed the whole class of professional athletes. The principle of the gradual increase and diminution of work on which it is founded is absolutely sound, and is one of the essential principles of the “Ling” system of physical training. The fault lay in the ignorant and pedantic application of the principle. No deviation from its routine was permitted, and no account was taken of the individual’s actual condition. Philostratus tells a story of a contemporary athlete, Gerenius, who three days after winning an Olympic victory celebrated his success by a banquet at which he ate and drank things to which he was not accustomed. The next day, suffering from indigestion and want of sleep, he repaired to the gymnasium as usual, and being put through a more than usually severe course of exercise by his irritated trainer, actually died under the treatment. The tetrads, says Philostratus, have ruined all athletic training; and the purpose of his book is to show the absurdity of such artificial systems, and by introducing sounder principles of athletics to restore the glory of the stadium. The main principle which he inculcates is the necessity of a thorough knowledge of the human body, and of suiting the training to the individual’s requirements. He discusses at length the various physical qualities which are best for different sports,—the qualities of the boxer, the wrestler, or the runner,—and gives a fanciful classification of the different types of athletes, the lion type, the eagle type, the bear type, the plank type, the rope type! He has a profound reverence for the traditions of Olympia, and regards the Eleans as the sole repositories of athletic lore, accepting all that they tell him with childlike simplicity. With much common sense he mingles an amount of rhetoric and fancifulness such as we should expect from the credulous biographer of Apollonius of Tyana, which seriously diminishes the practical value of his work.[283]