I've come to realize that one cannot fully understand Ong without understanding his theology and how it relates to secular knowledge. It's important to note that Ong held a Scotist rather than Thomistic view of the Incarnation: that the Incarnation was always part of the divine plan, not a reaction to the fall. For Ong, our growing and ever changing understanding of secular knowledge is, part and parcel, our growing and ever changing understanding of God's creation.
from "The Apostolate of Secular Arts and Sciences." American Catholic Crossroads: Religious-Secular Encounters in the Modern World. 1959. Westport, CT: Greenwood Press, 1981. 118-56.
"If through the Incarnation the Church is committed to cosmic history, by the very same token she is committed to secular learning, for secular learning is not a thing apart from cosmic history, something superadded to it, but rather [page break] something within that history which develops in articulation with earlier events in the same history, to protract and fulfill them. When the cosmos has attained a certain degree of maturity, God creates the first human soul and infuses it into the matter prepared for it. As the human race develops, human understanding and learning develop, for learning, whether that of letters or of science, does not exist fullblown at the beginning of human civilization. It is essentially not only something which puts in it seminal appearance with man himself at a certain time in cosmic history -- some five to ten billion years from the beginning of the universe we know -- but also something which has a measured growth. The growth of knowledge protracts the growth of the cosmos itself which has given birth to man, for through this growth of knowledge the cosmos comes to its own fuller and fuller maturity, in which it becomes aware of itself and its relationship to God" (138-39).
As I have said before, this conception of "knowledge in time" (to use Ong's own phrase) is central to his thought. Some of his critics, not realizing this, cite new knowledge as evidence which discredit's Ong's ideas. Denise Schmandt-Besserat's Before Writing is one such work a vocal critic likes to cite and continues to cite as early as a few months ago. Ong's review essay of Schmandt-Besserat's work ("Digitization, Ancient and Modern: Beginnings of Writing and Today's Computers," originally published in Communication Research Trends 18.2 (1998): 3-21, and republished in An Ong Reader) is an excellent example of how Ong regards new knowledge not as a threat but as something to embrace and incorporate.