Page:Philosophy and Fun of Algebra.djvu/58

PHILOSOPHY AND FUN OF ALGEBRA place you wish to go to. It is by no means warranted to take you safely back.

The advantage of Boole's method is that it is warranted to bring you safe down somewhere on solid earth,—not always the exact place you started from, but a safe and clean place of some kind—and to deposit you steady on your feet, with a compass in your pocket which will show you a straight way home. 54