ECONOMIST: Scientific dissent should be silenced. It can, it is true, do harm. When AIDS first reared its ugly head, no one knew what caused it. Gradually, the virus responsible was isolated, identified and then attacked successfully with drugs designed specifically to inhibit its reproduction. A few scientists, though, refused to accept the evidence, and some politicians used their arguments to justify inaction. Since one of those politicians was Thabo Mbeki, then president of South Africa, hundreds of thousands who might have been saved by an anti-AIDS policy grounded in scientific reality died as a result of his policies.