THE publication of the present reprint of De Morgan's Elementary Illustrations
of tlie Differential and Integral Calculus forms, quite independently of its
interest to professional students of mathematics, an integral portion of the
general educational plan which the Open Court Publishing Company has been
systematically pursuing since its inception,—which is the dissemination among
the public at large of sound views of science and of an adequate and correct
appreciation of the methods hy which truth generally is reached. Of these
methods, mathematics, by its simplicity, has always formed the type and ideal,
and it is nothing less than imperative that its ways of procedure, hoth in the
discovery of new truth and in the demonstration of the necessity and
universality of old truth, should be laid at the foundation of every
philosophical education. The greatest achievements in the history of
thought—Plato, Descartes, Kant—are associated with the recognition of this
principle.