“You will see it written that Hadamard was the last of the universal mathematicians (see: last person to know everything) —the last, that is, to encompass the whole of the subject, before it became so large that this was impossible. However, you will also see this said of Hilbert, Poincare, Klein, and perhaps of one or two other mathematicians of the period. I don't know to whom the title most properly belongs, though I suspect the answer is actually Gauss.”

— John Derbyshire (2003), Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics [1]

“The greatest mathematicians, as Archimedes, Newton, and Gauss, always united theory and applications in equal measure.”

— Felix Klein (c.1900) (Ѻ)