Knock witnesses were unduly influenced by things they had already seen 

The trouble with some apparition stories about Jesus' mother, is that they might look convincing, particularly when they are in the past and look convincing simply because we forget that they might have arisen in a superstitious culture that programmed people to be prone to visions.  If a hundred stories are cooked up one of them might look good while the others fade away into forgotten memories.

The Knock vision has some similarities to the White Lady legends. The lady is in white and somebody usually is about to die when she appears. Judith Campbell's mother comes to mind. The stories are linked to purity and husbands feature in the visions. A man bowing at Mary at Knock was presumed to be St Joseph.

The White Lady nearly always is silent and looks pale and is in a white dress. Wedding dresses feature a lot and the Knock vision could be interpreted as a bride with a crown.

Interestingly, the Malta White Lady appears after 8 pm. So does our Knock lady. Malta Lady has a shadow that she wants you to get trapped in. A shadow – a dark mearing – was reported at Knock.

The witte wieven, white maidens, of the Netherlands usually come across and kindly and prayerful. Fog and mist if it is mere wisps is usually taken to be a vision of one of those ladies.

The Silk Lady of Louisana wears a white dress and like the Knock lady her feet do not touch the ground.

Nothing in Knock seems that out of the ordinary when you count the White Lady stories from all over the world.

Lisa Bitel wrote about how believers in visions see visions in things that are plainly not visions.  They interpret shapes as being Mary though no sceptic can see how it could pass for Mary.  She wrote that a triangular shape of light will be imagined to be the Virgin Mary (Bitel 2009: 85–6).

The Knock vision

When investigating apparition claims, if the visionary seems to be copying from something else, the vision is regarded as false. Imitation is regarded as clear evidence that the vision claims are not to be taken seriously. That is Church policy. But it has not stopped the Church from following apparitions that do copy other apparitions or accounts that plagiarise. There must be no copying. If you see an image of Mary that matches a statue of her that you have in the house, experts will think you are pretending to see her and are describing the statue when you describe the vision because it helps you keep your story straight and sound more real.
 
On the night of the 21st of August 1879 the Virgin Mary flanked by St Joseph and a bishop thought to be St John the Evangelist and an altar with a lamb and cross on it allegedly appeared on the gable wall of the Parish Church for a few hours. Fifteen people witnessed the vision including a child of five (page 60, The Evidence for Visions of the Virgin Mary) and stood watching it for two hours allegedly in torrential rain.
 
The claims were investigated by a commission not long after.
 
Top witness Mary Beirne stated, " In the figure of St. Joseph the head was slightly bent, and inclined towards the Blessed Virgin, as if paying her respect; it represented the saint as somewhat aged, with gray whiskers and grayish hair. The third figure appeared to be that of St, John the Evangelist ; I do not know, only thought so, except the fact that at one time I saw a statue at the chapel of Lekanvey, near Westport, County Mayo, very much resembling the figure which stood now before me in group with St, Joseph and Our Blessed Lady, which I beheld on this occasion. He held the Book of Gospels, or the Mass Book, open in his left hand, white he stood slightly turned on the left side towards the altar that was over a little from him. [ORIGINAL SAYS, "I NEVER SAW FIGURES OR STATUES LIKE THEM" - THIS WAS OMITTED AS IT OBVIOUSLY CONTRADICTS HER CLAIM THAT SHE SAW A STATUE OF JOHN LIKE THE ONE IN THE VISION - READ ON TO SEE WHAT SHE CLAIMED] I must remark that the statue which I had formerly seen at Lekanvey chapel had no mitre on its head, while the figure which I now beheld had one — not a high mitre, but a short-set kind of one. The statue at Lekanvey had a book in the left hand, and the fingers of the right hand raised. The figure before me on this present occasion of which I am speaking had a book in the left hand, as I have stated, and the index finger and the middle finger of the right hand raised, as if he were speaking, and impressing some point forcibly on an audience. It was this coincidence of figure and pose that made me surmise, for it is only an opinion, that the third figure was that of St. John, the beloved disciple of our Lord. But I am not in any way sure what saint or character the figure represented, I said, as I now expressed, that it was St. John the Evangelist, and then all the others present said the same — said what I stated."
 
Knock witness Catherine Murray also claimed to have seen the Lecanvey statue and said it resembled the bishop figure.
 
It is true that there is no evidence that the statue was there but what if it was? Whatever the truth is, the fact remains is that she is saying the image of the bishop was seen somewhere before.
 
The accounts made by the visionaries to the commission describe Mary standing between two saints one of whom was a bishop wearing a low mitre. The scene matches the depiction of Mary between a saint and a bishop like that in a stained glass window in nearby Ballyhaunis (pages 237-240, Knock The Virgin's Apparition in the Nineteenth Century) too well to be a coincidence. Most of the visionaries probably saw it and it influenced what they thought they saw at the gable. Patrick Hill (same source) declared that the images he saw on August 21 resembled holy pictures he had seen. The Ballyhaunis window has Mary dressed in white standing higher than the other two figures. One figure is bowed to her. All this was duplicated at Knock. And there was a mitred figure on the other side of her as well in the Ballyhaunis image. The bishop figure there was St Augustine. He resembled the John figure at Knock.
 
The Temperance medal, which would have been familiar to many at Knock, which showed an altar with angels flying around it and a lamb on it with a cross behind the lamb is a perfect match for the altar seen at Knock (page 240, Knock The Virgin's Apparition in the Nineteenth Century). The medal and the vision depicted the altar as emitting light. Some visionaries denied seeing the cross and the altar.
 
 
 
 
All this suggests that the visionaries were not sure what they saw and their memories got mixed up with other things they had seen.
 
Suppose God really did engineer the image of the Lamb on the altar with the cross at Knock. He would be advertising the temperance medal. The temperance medal carries the words In Hoc Signo Vinces. Jesus supposedly said those words to Constantine to encourage him in religious war. The medal implicitly encourages the notion that religious visions have the right to command war! Dangerous!

It is felt that lamb of God emblems and cards that were given out as gifts at Catholic schools were possibly the inspiration for the lamb on the altar with the cross.   

Here is a story from the Duchas collection of tradition and heritage.  The schoolchildren in the Republic of Ireland in the 1930's had to talk to an older person about tradition and write down what they said as part of a school essay.  This enterprise became the National Schools Folklore Collection.  The story comes from Claremorris which is not far from Knock.  It shows how apparitions that nobody said were Mary were taken to be of fairy women.  The story only guesses that this "big lady dressed in white" is a fairy woman.  If it could be Mary then why not?  The Collection is remarkable for how little interest the Knock visions of 1879 got from locals.  No child in Knock wrote an essay about the visions.  That is what you would expect if the vision story was seen as just another tradition in an area saturated with magic.

Mrs Jennings was born about 1850 and would have been about 29 or 30 at the time of the Knock vision.  It is possible her father reported this experience in the 1870's.  Why the vision was not taken to be of Mary is bizarre!  If it had not been for a figure like a bishop at Knock the apparition could have been interpreted very differently.  Remember the tradition about the cross and the altar been seen is uncertain and many witnesses never mentioned it. 

Knock The Virgin's Apparition in Nineteenth Century Ireland shows that the original Knock apparition was reported by people and a society that delved heavily into superstition and often couldn't separate reality from religious fantasy. The apparition then in that context would certainly be an encouragement to such a society. If you honour Mary, don't insult her by claiming that the Knock apparition was really her! If you claim that it was, you are saying she was a catalyst for superstition.