> On Gordan's supposed quote (which I believe he did say
> in fact) "this is not mathematics it is theology", the earliest
> source I have found is Max Noether's obituary of Gordan in
> MATHEMATISCHE ANNALEN 75 (1914) 1-41, page 18....
The story is told by Felix Klein in the _Lectures on the
Development of Mathematics in the 19th Century_, and his language
sounds as though he had personal knowledge of it:
The unusual nature of [Hilbert's] work produced quite diverse
reactions. I resolved to draw Hilbert to Goettingen at the
first opportunity. Gordan at first reacted negatively, saying
"This is not mathematics, it is theology." But later he said
"I have become persuaded that even theology has its uses." In
fact, he himself substantially simplified Hilbert's argument.
(At the moment, I don't have the German at hand, but it's fairly
late in the book, following the discussion of Hilbert's work.)
William C. Waterhouse
Penn State