There were no historical instances. This is exactly why this discovery is considered so great. It is a feature of a truly truly great discoveries that after they are made, people ask: why did nobody think like this before ?
Set theory is the best example of this I can think of.
Comparable perhaps only to Kepler's First law and General Relativity. I do not know any other examples of such radical changes in our thinking, made by one person.
Perhaps other members will give other examples.