Without any doubt at all, teacher quality is the fundamental differentiator. Not just, incidentally, of education, but I would argue, probably the biggest single differentiator of success for the nations of the 21st Century.

Summary

This quote emphasizes the critical role that teacher quality plays, not only in education but also in determining the success of nations in the 21st century. It suggests that the caliber of teachers stands as the most significant factor that sets educational systems apart and influences the outcome of a country's development. By implying that teacher quality is the "fundamental differentiator," the quote underscores the importance of investing in and prioritizing the ability and competence of educators for achieving success at both individual and national levels.