I’ve been away from news media for a few weeks, but as I scroll down the page of aggregated content on Google News, past Pope Francis in Rio and a jewelry heist on the French Riviera, I notice this BBC headline: “Scientists can implant false memories in mice.” The accompanying picture shows a small brown mouse, wearing a crown of implanted optical fibers and meditating upon the strange experiences to which he has lately been subjected.

As I wonder how it feels to be that mouse, I’m reminded of Thomas Nagel’s famous 1974 essay, “What is it like to be a bat?”—a landmark in the philosophy of mind. Nagel’s thesis was that there is “something that it is like” to undergo particular states of consciousness or being; there is a first-person perspective (for which the technical word is qualia) that will forever elude reductionist explanation. But the inscrutable depths of a laboratory mouse or of his flying cousin are beside the point; what we really want to know is what it is like to be a human being.

Some neuroscientists will tell you that it’s just a matter of time before we possess a complete physicalist map of mental states. I’m certain they are wrong and Nagel is right.