While it is true that the East and West have found the need to define matters, depending on the heretical teachings of the time, I don't find a parallel to the Scholastic school that followed St. Thomas Aquinas. Wasn't the distortions and extreme speculations part of Luther's rebellion? The only thing I can think of that is similar in the East is the Alexandrian school of thought in interpreting Scripture that took analogy to the extreme - which seemed to be taken up in some Medievel thought in the West. I wonder if the East ever speculated on how many angels could fit onto the head of a needle?! Such matters had little to do with defining what we believe. But perhaps you are correct, and given the political and religious backgrounds in our respective regions, the roles might have been reversed.
Regards
I see--you were referring to theologians, not the magisterium, defining/refining theological understanding of the mysteries. True. But the development of Scholasticism was directly in response to the budding commercial and political changes in the West. With the growth of commerce, the growth of kingship, with the great project to recover as much of the ancient knowledge lost at the Fall as possible (that's the project of the schools and universities in the 11th-13thc--Richard Souther, Scholastic Humanism and the Unification of Europe is the best source on this now) etc. came new questions: how does mystery X apply to this new development in war, government, commerce, intellectual life.
The East did not experience that same pattern. They had always been the more developed commercially and politically but then spent the period after 900 fighting off the Turk, exactly at the time that the West was emerging from the last great obstacle to it's take-off--the Viking invasions in the north and the Saracen raids in the Western Mediterranean.
Take the doctrine of transubstantiation, for instance. Berengar mounted a frontal attack on real presence (though Henry Chadwick thinks he was not really denying it, most scholars think he was; the controversy between Ratramnus and Paschasius in the 800s did not involve from either disputant an attack on real presence). In response to Berengar's denial, theologians spent the 1100s trying to think through a credible explanation for how the mystery they already believed in could be better understood. No such attack took place in the East. The same goes for questions about marriage and divorce, crusades, just war, usury etc. John W. Baldwin's book, Masters, Princes and Merchants, Princes (Johns Hopkins, 1972?) shows how the late 1100s early scholastics were responding to these kinds of practical questions and that's what birthed scholasticism.
The East never had the Enlightenment, which challenged belief in miracles, in revelation etc. So the West's theologians refined more and more the explanations for what both East and West had always believed. Anselm's Atonement theology was a direct response to challenges by the Jewish community in France--he owed them an accounting of our faith, as St. Peter tells us always to be ready to render.
So yes, it's true that the West, both magisterially and by theologians' work in the schools, has done more defining and refining. But in both spheres, it's because more questions were raised in more fundamental ways in the West than in the East. And in large part that's because the East was largely under the domination of Islam.
There may also be cultural differences at work: the Greek love of art and philosophy, the Roman love of law and structures. But I would be very, very cautious about giving this much explanatory power. To begin with, it's mostly a caricature of the two cultures, though, like all caricatures, it has a germ of truth to it. Secondly, even to the degree that this cultural difference exists, other, much better explanations (as I tried to give above) are more credible.