A logic machine is a device, electrical or mechanical,
designed specifically for solving problems in formal logic. A logic
diagram is a geometrical method for doing the same thing. The two
fields are closely intertwined, and this book is the first attempt in
any language to trace their curious, fascinating histories.
Let no reader imagine that logic machines are merely the play-
things of engineers who happen,to have a recreational interest in
symbolic logic. As we move with terrifying speed into an age of
automation, the engineers and mathematicians who design our
automata constantly encounter problems that are less mathemati-
cal in form than logical. It has been discovered, for example,
that symbolic logic can be applied fruitfully to the design and
simplification of switching circuits. It has been found that electronic
calculators often require elaborate logic units to tell them what
steps to follow in tackling certain problems. And in the new field
of operations research, annoying situations are constantly arising
for which techniques of symbolic logic are surprisingly appropriate.
The last chapter of this book suggests some of the ways in which
logic machines may play essential roles in coping with the stagger-
ing complexities of an automated technology.