Agriculture: The plow and observing greater abundance. (Also preceding even that: observing that seeds produce more plants)
Helio-Centrism: The telescope and seeing the moons of Jupiter revolving around it. Also discovery of the ellipse and the observation that it accurately describes planetary orbits
Direct and Reciprocal Monetary Gifting: Double entry bookkeeping and its subset cost accounting and cost accounting’s conventions. The new observation that applying monetary policy directly and reciprocally as a substantial discount at the point of retail sale eliminates any possibility of inflation, and in fact the further totally new observation that this policy can beneficially integrate price deflation into profit making systems.