I have received a number of interesting responses to my claim in yesterday’s post that it is possible for groups of people to have the same non-veridical vision (that is, hallucinations).  I used the phenomenon of the Blessed Virgin Mary: she seems to appear a good deal, to groups of people – sometimes large groups.  In this post I thought I would respond to two of the highly intelligent demurrals.   DEMURRAL: As a former evangelical Protestant we believed that Roman Catholics who claim to see the Virgin Mary as a group are in a state of emotional hysteria and seeing an illusion not experiencing a group hallucination.  An illusion is a distorted perception of something that really is present, such seeing a stain on a wall or a cloud formation in a photograph and seeing the Virgin Mary or Jesus in it.  Many thousands of Roman Catholics claimed to have experienced a visitation of the Virgin Mary in Fatima Portugal not due to seeing and hearing a woman in flowing robes speak the same [...]