Francis Ysidro Edgeworth

"By the early 1880s it is clear his competence had expanded to the full spectrum of the mathematical sciences: Fourier's theory of heat, Poisson's mechanics, Cournot, Gossen, Jevons and Walras on mathematical economics, Airy, Thomson and Tait, and Clerk Maxwell on physics, and, above all, Laplace on the theory of probability."

"Edgeworth lacked the force that produces impressive treatises and assembles adherents; amiable and generous, he never asserted himself in any claims of his own, he was over-sensitive on the one hand, overmodest on the other; he was content to take a backseat behind Marshall whom he exalted into Achilles; hesitating in conversation, absent-minded to a pathological degree, the worst speaker and lecturer imaginable, he was personally ineffective -- unleadedy is, I think, the word."

"Marshall, remembering his mixed parentage, used to say 'Francis is a charming fellow, but you must be careful with Ysidro!'""