One of the volumes amongst the IET’s collection of S P Thompson’s rare books is an English translation from the Latin version of Emanuel Swedenborg’s book, ‘Principia, volume1’. This volume was originally published in 1734 (translation published in 1912).

This might not appear too interesting so far, but not only is the original author, Swedenborg, a fascinating character involved with mysticism, but we have also just discovered two letters within the translated volume with further links to mysticism.

Emanuel Swedenborg (1688-1772)

Emanuel Swedenborg was a Swedish scientist, philosopher, theologian, revelatory and mystic who is best known for his book on the afterlife, Heaven and Hell (1758). A portrait of Swedenborg by Carl Frederick von Breda is shown below:


Swedenborg had a notable career as an inventor and scientist, then when aged 53, in 1741 he entered a spiritual phase in which he began to experience dreams and visions. This led to a ‘spiritual reawakening’ in which he received a revelation that he was to write The Heavenly Doctrine to reform Christianity. In that volume he claimed that his spiritual eyes had been opened, so that from then on he could freely visit heaven and hell and talk with angels, demons and other spirits.

The philosopher Immanuel Kant (1724-1804), became a strong critic of Swedenborg and his writings and he described Swedenborg in 1766, as a ‘spook hunter’ and ‘without official office or occupation’.

Prior to Swedenborg’s spiritual phase, during his scientific period, which began in 1715 and lasted for the next two decades, he devoted himself to natural science and engineering projects and he was offered, but declined, the chair of mathematics at Uppsala University, Sweden, in 1724 (the oldest university in the Nordic countries, founded in 1477). During the 1730s, Swedenborg undertook many studies of anatomy and physiology. He had the first anticipation as far as is known, of the neuron concept. He also had prescient ideas about the cerebral cortex, the hierarchical organisation of the central nervous system, the functions of the pituitary gland, and the association of frontal brain regions with intellect.

The Principia


In the 1730s as Swedenborg became increasingly interested in spiritual matters and was determined to find a theory which would explain how matter relates to spirit. Swedenborg’s desire to understand the order and purpose of creation first led him to investigate the structure of matter and the process of creation itself. In the Principia he outlined his philosophical method, which incorporated experience, geometry (the means whereby the inner order of the world can be known), and the power of reason.

The Letter Discoveries!

The 1912 translation into English of Swedenborg’s Principia was by James R Rendell and the Reverend Isaiah Tansley with an introduction by Tansley and a forward by Professor Sir William Barrett FRS. The first letter found in the book, dated 4 June 1912, was from Isaiah Tansley and sent to S P Thompson. The letter, on headed paper of The New Church College, Devonshire Street, Islington, London, where Tansley was the Secretary, thanks Thompson for his review of the introduction. The letter says;

“Dear Sir, you were kind enough by the request of Sir W F Barrett, to read through my humble effort to write an introduction to Swedenborg’s principia, and make valuable notes on the proof sheets. I wish to thank you for doing me this great favour; & I wish to ask you whether you would allow me to acknowledge this in a brief note at the final of the first page. It would simply state the fact: Sir W Barrett has warranted from me to do the same in response to his kindness in the same direction. Some few years ago, you may remember, I wrote you by request of the Swedenborg Society, to ask you to write the introduction, but you did not see your way. You will not particularly object to me reminding you of this fact. I have the honour to remain faithfully yours Isaiah Tansley.”

The first page of the letter is shown below;


Tansley was the pastor for 11 years, at the start of the 20th century, of the New Church (Swedenborgian) near Crystal Palace Station, known as the ‘concrete church’ being one of the earliest buildings erected in mass-concrete in 1883. According to the Norwood Society’s website, Tansley was a learned and warm-hearted man who was very absent minded. It tells the following story of his forgetfulness;

“There is a story that his [Tansley’s] wife supplied him with a large stock of umbrellas as he had the habit of taking one with him to the New Church College in London where he taught and returning home without it. One morning, his stock of umbrellas exhausted, he arrived at London Bridge station and absent-mindedly took an umbrella from the luggage rack, to be confronted by the angry owner who asked if he was in the habit of appropriating other people’s property. Returning that evening, he remembered to collect his umbrellas, all six of them. Boarding the train at London Bridge he found himself sitting opposite the angry gentleman of the morning, who remarked: “Ah, sir, I see you have had a profitable day”!

The Letter from Sir William Fletcher Barrett (1844-1925)

The second letter found in the volume, dated 13 June 1912, is from Sir William Fletcher Barrett to S P Thompson and also refers to Thompson’s review of Tansley’s introduction. The letter says;

“My dear Thompson, the Swedenborg Society write to me asking me ‘to express to Prof. S P Thompson their sincere thanks of his great time that he has taken in viewing Mr Tansley’s preface, and their appreciation of the value of his criticism.’ They also enclose me a cheque – though you were kind enough to say you wouldn’t take it – I enclose 5 guineas, as I told the Swedenborg Society I should do so. Feel it is an inadequate premium for the time you gave these months, so hope your scruples will be overcome.

I very much wish I could come on to the optical convention, but if I go to the Royal Society celebrations a months’ hence, I can’t afford time & money for a double journey. I don’t know what to do about the paper on the entoptiscope [a machine invented by Barrett] I promised, it needs the instrument and my presence to demonstrate it.

I should like to show my interest also in your Presidency, but rail and hotel means £5 to £10. I hope you are well, with kindest regards, yours sir sincerely, W F Barrett.” The first and fourth pages of the letter are shown below;


This is where the next link to mysticism raises its head. Sir William was not only a physicist but he was also a parapsychologist.

Barrett became interested in the paranormal in the 1860s after having an experience with mesmerism. Barrett believed that he had been witness to thought transference and by the 1870s he was investigating poltergeists. In September 1876 Barrett published a paper outlining the result of these investigations and by 1881 he had published preliminary accounts of his additional experiments with thought transference in the journal Nature.

The publication caused controversy and in the wake of this Barrett decided to found a society of like-minded individuals to help further his research. Barrett held a conference between 5–6 January 1882 in London. Then in February the Society for Psychical Research (SPR) was formed. Barrett was a Christian and a spiritualist member of the SPR. Although he had founded the Society, Barrett was only really active for a year, and in 1884 founded the American Society for Psychical Research before his paranormal research diminished significantly. However, he became President of the Society in 1904 and continued to submit articles to their journal, even with a diminished interest in the subject.

Barrett had a special interest in divining rods and in 1897 and 1900 he published two articles on the subject in ‘Proceedings of the SPR’. After experimenting with dowsers, Barrett concluded that the ideamotor response was responsible for the rod’s movements but in some cases the dowser’s unconscious could pick up information by clairvoyance. He was also a believer in telepathy.

Barrett drew criticism from researchers and sceptics and the sceptic Joseph McCabe wrote that Barrett “talks nonsense of which he ought to be ashamed”, as he had poor understanding of conjuring tricks and failed to detect the fraud of the medium Kathleen Goligher. An image of Barrett is shown below;


At least the mystery of the letters is now solved!