De Morgan, Augustus (du môr'gun) [key], 1806–71, English mathematician and logician, b. India. A noted teacher, he was professor of mathematics (1828–31, 1836–66) at University College (now part of the Univ. of London) and a founder and first president (1865) of the London Mathematical Society. Known as a reformer of logic, he developed a new logic of relations that he summarized in Syllabus of a Proposed System of Logic (1860). His works include An Essay on Probabilities (1838), Formal Logic (1847), Trigonometry and Double Algebra (1849), and A Budget of Paradoxes (1872).
