AUGUSTUS DE MORGAN,

OF TRINITY COLLEGE, CAMBRIDGE,

PROFESSOR OF MATHEMATICS IN UNIVERSITY COLLEGE, LONDON.

The root of all the mischief in the sciences, is this; that falsely

magnifying and admiring the powers of the mind, we seek not its real

helps.—BACON.

First notions of logic (preparatory to the study of geometry) · 第 2 / 28 题