Anyone who regards games simply as games and takes work too seriously has grasped little of either." So wrote the German poet Heinrich Heine a century ago. In today's world the division of
work and play persists. Old prejudice still holds that the playing of games is an activity for children,
not useless perhaps, but certainly not the responsible and serious work of adults.
Heine intuitively foresaw what modern psychology has since asserted. Games are not only
necessary for the development of a child's self-awareness; they are also needed by adults,
especially when their work is repetitive and uncreative. The word "games," as it is used in this book,
is general and covers a variety of quite complex activities. However, it is those games based on
mathematical or logical principles that are among the most absorbing and creative. Indeed, the
great mathematicians and scholars of the past often applied their skills to the solution of logical and
mathematical games.