"Tamper with the deepest mysteries – the source of life, the essence of self – only if prepared for consequences of the most extreme and dangerous kind."
-- Adalbert Waffling's 1st Fundamental Law of Magic (TBB/WHH)
Adalbert Waffling was a famous magical theoretician and the author of Magical Theory (PS5, FW).
"waffle" Brit - to talk on and on without saying much of anything
There is an inconsistency of dates with Waffling. His date of birth is given as 1899 on his Famous Wizard Card. However, in DH he is mentioned as a correspondent of Dumbledore's when the latter was a young wizard (DH2). The implication is that Waffling was at that time an older, more important person in wizarding academia. It's possible that Elphias Doge, who wrote the eulogy from which the reference comes, simply misremembered something which happened a century ago. However, if we accept the DH reference as correct, we must consider the FW reference to be suspect.