Logic is unproductive, and so is accountancy; but if books are not properly kept, the most productive enterprise may come to ruin; and neglect of logic, still more contempt for it, means that the general standard of thinking deteriorates. And whereas you can totally resign your book-keeping to an accountant, you cannot leave all your thinking to a logician.
(P. T. Geach, "On Teaching Logic," Philosophy 54 [January 1979]: 5-17, at 14)
Keith Burgess-Jackson, J.D., Ph.D. 
