What if your mind is not only in your brain? How exactly would your mind extend across brain, body and beyond? Philosopher Dave Chalmers claims that if his iPhone were implanted in his head, it would just speed up processing; it is already part of his mind. Claims about the extended mind have been around for a long time: for the Romans, your iPhone equivalent was your slave. We are all out of our heads, argues Miranda Anderson (University of Stirling; University of Edinburgh), and we always have been.