"The proof of this theorem of Hilbert's and of others is very abstract, but in itself quite simple and hence logically compelling. And for just this reason this work of Hilbert's ushered in a new epoch of algebraic geometry. But application to invariant theory is just as simple, but I can analyze it here even less. The whole question of the finiteness of the invariants, which Gordan had been able to solve for binary forms only by means of comprehensive calculations (see p. 290), is here solved, with one stroke, for forms with arbitrarily many variables. Because of its uniqueness, this work was first received with very diverse reactions. I had then resolved to draw Hilbert to Goettingen at the earliest opportunity. Gordan at first declined, saying, "It is not mathematics, it is theology" But later he said: "I have convinced myself that even theology has its merits". In fact, Gordan himself later on much simplified Hilbert's basic theorem (Muenchener Naturforscherversammlung 1899)."