 1920 Start of the “Grundlagenstreit” (Foundational Debate) with Brouwer’s lecture at the “Naturforscherversammlung” in Bad Nauheim, published in 1921, “Does Every Real Number Have a Decimal Expansion?”; the debate was amplified by Weyl’s defence of intuitionism in 1921, “On the New Foundational Crisis of Mathematics”; Hilbert responds in 1922, “The New Grounding of Mathematics”.