We have been brought up to believe that our minds are inside our heads, that mental activity is nothing but brain activity. Instead, I suggest that our minds extend far beyond our brains; they stretch out through fields that link us to our environment and to each other. Mental fields are rooted in brains, just as magnetic fields around magnets are rooted in the magnets themselves, or just as the fields of transmission around mobile phones are rooted in the phones and their internal electrical activities. As magnetic fields extend around magnets, and electromagnetic fields around mobile phones, so mental fields extend around brains. Mental fields help to explain telepathy, the sense of being stared at and other widespread but unexplained abilities. Above all, mental fields underlie normal perception. They are an essential part of vision.