I pin it down to historical happenstance: Had the byzantines not
  sent over a smart dude to re-educate the Latin West at the
  otherwise doomed council of Florence, all Europe would have is
  Aristotle when Byzantium (the carrier of Classical Greek
  tradition and knowledge) fell... Best two paragraphs - out of
  the Council of Florence page on Wikipedia: === The struggle for
  East-West union at Ferrara and Florence, while promising, never
  bore fruit. While progress toward union in the East continued to
  be made in the following decades, all hopes for a proximate
  reconciliation were dashed with the fall of Constantinople in
  1453. Perhaps the council's most important historical legacy was
  the lectures on Greek classical literature given in Florence by
  many of the delegates from Constantinople, including the
  renowned Neoplatonist Gemistus Pletho. These greatly helped the
  progress of Renaissance humanism.[10]"