How Free Is Your Free Will?

I’ve mentioned Carl Zimmer’s fascinating book Parasite Rex before. He’s returned to one of its themes (that viruses alter host behaviour) in his blog. In "The Return of the Puppet Masters" he leads off with the rather startling question: are brain parasites altering the personalities of three billion people? Go and read it. I’m just mindful of the fact that we will need to get a cat to keep the mouse population down around the farmhouse. If I don’t already carry Toxoplasma gondii in my brain, I probably soon will do.