"Jeffrey D. Sachs is a great man, doing great things for people around the world," began a note from Trey Strawn of Winter Springs, Fla. "His battle against poverty is inspiring. 'Welfare States, beyond Ideology' [Sustainable Developments], however, is unscientific, biased and wrong." Find out why readers such as Strawn responded with some heat to Sachs's November 2006 column in the letters below. Correspondents were also drawn to fiery phenomena in other articles in that issue: from the mysterious sparkings in our brains' inner space explored in a special section on mirror neurons to the first light of outer space described in an article about the Dark Ages of the universe.

I am a clinician who often works with children and adolescents with Asper?ger's syndrome, and I am an author of two books on the subject. The research and theory described in "Mirrors in the Mind," by Giacomo Rizzolatti, Leo?nardo Fogassi and Vittorio Gallese, and in "Broken Mirrors: A Theory of Autism," by Vilayanur S. Ramachandran and Lindsay M. Oberman, are consistent with, and help to explain, what these children experience and what others experience when they are with them. Those autistics who are higher functioning can learn about our language, such as the meaning of specific metaphors. They can even use these metaphors by translating, although not from their own intrinsic understanding.