I know you're on my side," an immunologist once remarked to me as we discussed the politics of vaccination. I did not agree with him, but only because I was uncomfortable with both sides, as I had seen them delineated. The debate over vaccination tends to be described with what the philosopher of science Donna Haraway would call "troubling dualisms." These dualisms pit science against nature, public against private, truth against imagination, self against other, thought against emotion, and man against woman.