He claimed that the game of chess was an image of war, and it was possible to play chess as a mental exercise for the solution of military tactics. Chess could not be played for a stake, but if a player was playing for a mental exercise, he was not doing anything illegal. Provided the player took care that his fondness for chess did not cause him to break any other rule of life, he saw no harm in playing chess. He played chess himself, defending his practice by the example of many of his companions.