Paul du Bois-Reymond

Paul David Gustav du Bois-Reymond (2 December 1831 – 7 April 1889) was a German mathematician who was born in Berlin and died in Freiburg.

His interests included Sturm–Liouville theory, integral equations, variational calculus, and Fourier series.

In a paper of 1875, du Bois-Reymond employed for the first time the method of diagonalization, later associated with the name of Cantor.

He is also associated with the fundamental lemma of calculus of variations of which he proved a refined version based on that of Lagrange.

Yet when one thinks boldly and freely, the initial distrust will soon mellow into a pleasant certainty ... A majority of educated people will admit an infinite in space and time, and not just an "unboundedly large".