As a teenager, Harriet Tubman suffered a traumatic head injury, which had a startling side-effect:
Then the pursuers would start after them. Advertisements would be posted everywhere. There was one reward of $12,000 offered for the head of the woman who was constantly appearing and enticing away parties of slaves from their master. She had traveled in the cars when these posters were put up over her head, and she heard them read by those about her--for she could not read herself. Fearlessly she went on, trusting in the Lord.
This fearless woman was often sent into the rebel lines as a spy, and brought back valuable information as to the position of armies and batteries; she has been in battle when the shot was falling like hail, and the bodies of dead and wounded men were dropping around her like leaves in autumn; but the thought of fear never seems to have had place for a moment in her mind. She had her duty to perform, and she expected to be taken care of till it was done.
I had given some accounts of Harriet's labor to the Anti-Slavery Society of Edinburgh, of which Eliza Wigham was Secretary. On the reading of my letter, a gentleman present said he would send Harriet four pounds if he knew of any way to get it to her. Eliza Wigham offered to forward it to me for her, and that was the first money ever received by me for her. Some twelve months after, she called on me again, and said that God told her I had some money for her, but not so much as before. I had, a few days previous, received the net proceeds of one pound ten shillings from Europe for her. To say the least, there was something remarkable in these facts, whether clairvoyance, or the divine impression on her mind from the source of all power, I cannot tell; but certain it was she had a guide within herself other than the written word, for she never had any education.
A great reward was offered for her capture, and she several times was on the point of being taken, but always escaped by her quick wit, or by 'warnings' from Heaven--for it is time to notice one singular trait in her character. She is the most shrewd and practical person in the world, yet she is a firm believer in omens, dreams, and warnings. She declares that before her escape from slavery, she used to dream of flying over fields and towns, and rivers and mountains, looking down upon them 'like a bird,' and reaching at last a great fence, or sometimes a river, over which she would try to fly, 'but it 'peard like I wouldn't hab de strength, and jes as I was sinkin' down, dare would be ladies all drest in white ober dere, and dey would put out dere arms and pull me 'cross.' There is nothing strange in this, perhaps, but she declares that when she came North she remembered these very places as those she had seen in her dreams, and many of the ladies who befriended her were those she had been helped by in her visions.
"Then she says she always knows when there is danger near her,--she does not know how, exactly, but ' 'pears like my heart go flutter, flutter, and den dey may say "Peace, Peace," as much as dey likes, I know its gwine to be war!' She is very firm on this point, and ascribes to this her great impunity, in spite of the lethargy before mentioned, which would seem likely to throw her into the hands of her enemies. Sarah Bradford, Scenes in the Life of Harriet Tubman (1869), 21,42,52,79-80.
As she recovered from this long illness, a deeper religious spirit seemed to take possession of her than she had ever experienced before. She literally "prayed without ceasing." Sarah Bradford, Harriet Tubman: The Moses of Her People (Applewood Books, 1886), 24.
Harriet, according to Bradford, had a premonition that Fanny Seward had died. In a dream, Tubman "saw a chariot in the air, going south, and empty, but soon it returned, and lying in it, cold and stiff, was the body of a young lady of whom Harriet was very fond, whose home was in Auburn, but who had gone to Washington with her father." Terrified by the dream, Tubman ran "to the house of her minister, crying out: "Oh, Miss Fanny is dead!" and the news had just been received. Kate Larson, Bound for the Promised Land: Harriet Tubman: Portrait of an American Hero (Ballantine, 2004), 372n41.
Assuming this is accurate, it invites one of two basic interpretations:
1. Her dreams and visions were hallucinations, caused by brain damage. But even on that interpretation, we might still view her hallucinatory dreams and visions as providential. They were a source of sorely-needed encouragement for a woman who had a grueling, harrowing life. And, indeed, they made her more devout and more effective.
2. However, as reported, her dreams and visions seem to be vertical. What she dreamt about came true.
This might be corroborated by the fact that despite exposing herself to constant danger, with a huge bounty on her head, she always managed to elude capture. Perhaps she was just lucky. Or maybe she did have premonitions, which alerted her to danger. What Bradford called her "inner monitor."
Yet her dreams and visions were undoubtedly related, in some way, to traumatic head injury. If they were veridical, how do we explain that?
i) It might be analogous to savant syndrome. Due to congenital brain damage, some people have below-average intelligence, yet they have islands of genius which offset the cognitive deficit. Almost as if their brain damage frees up a latent ability that's masked by a normal brain. Likewise, her dreams and visions seem like a compensation for her traumatic head injury.
ii) This, in turn, revisits the mind/body problem. There are two related models which are relevant to her situation:
a) Physicalists view the producer of consciousness. But William James viewed the brain as a receiver. The mind originates outside the brain. The dualist transmission theory stands in contrast to the physicalist production theory. It's like a telephone that receives signals. If damaged, that impairs or destroys reception.
b) On a related note with the "reducing value" or mental filter model popularized by Aldous Huxley. One function of the brain is to screen out extraneous "noise" so that we can concentrate on the physical world. It's like a tuner, which as a twofold function: to tune into certain signals, and tune out other signals. If you can hear everything, it's too distracting. Too much information is static. White sound. If the tuner or filter is disabled, there's nothing to modulate the flood of input.
iii) Finally, it's like those science fiction scenarios in which a spy has a little receiver implanted in his brain which enables him to hear messages that are inaudible to outside observers. This gives him uncanny knowledge of the situation on the ground.