While we typically hold up scientists, especially those who have made important discoveries, as paragons of rationality, numerous scientists have had fascinations with cryptids, psychic phenomena, and other aspects of the occult. And what some of these particular people believed may surprise you.

Top photo: A seance held by Eusapia Palladino at the home of astronomer Camille Flammarion in France on November 25, 1898. Photo by H. Mairet, via Musees de la Ville de Strasbourg.

1. Sir Isaac Newton and His Belief in the Occult

Ot may surprise folks who are familiar only with Sir Issac Newton's mathematical and scientific contributions that Newton was profoundly interested in the occult. Newton was a devout Anglican and an alchemist — neither of which was unusual for an English scientist in the 17th and 18th centuries. (Although many of Newton's particular religious beliefs, particularly his anti-Trinitarianism, would have been considered heretical at the time.) Still, it's can be difficult for some modern readers to reconcile Newton's mathematical descriptions of the universe with his obsessions with Biblical numerology, astrology, and a quest for the Philosopher's Stone.

Newton made no distinction between the scientific and the mystical. He believed that the world could be understood through mathematics as well as through secrets hidden in the Bible. Based on his interpretations of the Scriptures, he even estimated the date of the end of the world. (He pegged it at around 2060, although he was himself suspicious of people who thought they had the exact year down.) He thought he could divine the size of the Earth by studying the geometry of Solomon's Temple. He conducted numerous experiments in his quest to create the fabled Philosopher's Stone. And his work in religion and alchemy was just as detailed as his work in what we would today consider science.


There are some writers who believe that Newton made such powerful contributions to our understanding of the world not in spite of his more mystical beliefs, but because of them. His studies on optics had their foundations in alchemy. In trying to describe the behavior of the cosmos, he was trying to unlock the secrets of God's mechanisms. He simply used whatever tools he could find: mathematics, the Bible, alchemy, and other "sciences" we would now consider occult. Some of them worked out better than others.

2. Carl Linnaeus' Mermaids

It's really hard to fault the 18th century botanist, zoologist, and taxonomist Carl con Linné, better known as Carl Linnaeus, for considering the existence of the occasional mythological creature (which, admittedly, is less supernatural than cryptozoological). After all, when Linnaeus collected his Systema Naturae, a great many new species of creature were just coming to light — and once you've described a narwhal, the possibilities of the animal kingdom seem pretty endless. And to his great credit, Linnaeus' work did a lot to eradicate superstitions surrounding mythical animals. System Naturae included a section titled Animalia Paradoxa, which listed fantastical animals as well as animals that had been described by explorers, but whose existence seemed somehow suspect. Legendary animals like the satyr, the phoenix, and the manticore ended up on this list. (Linnaeus also engaged in some cryptozoological debunkery, once famously examining the "corpse" of a hydra and quickly declaring it a fake.) So did a few animals that turned out to be real, like Pseudis paradoxa, the shrinking frog, and the pelican, which Linnaeus thought was the product of some explorers' overactive imagination.


But there was one mythical animal that fascinated Linnaeus so much that he believed it just might be real: the mermaid. In the tenth edition of System Naturae, he describes a "siren" specimen housed in a museum in Leyden, although he does call the creature "paradoxical" (mostly because it was supposed to be a marine mammal with large ears and a neck). The siren was only revealed as a fake much, much later, thanks to X-rays of the specimen. In a letter to the Swedish Academy of Sciences, Linnaeus confessed that he was unsure of the existence of such a creature, but it was clear that he had a profound interest in their possible existence.

When a supposed mermaid was reported to have been caught off the coast of Jutland, Linnaeus excitedly hoped it prove a breakthrough in natural history, but the body was exposed as a fake before he could make the journey to see it himself. It wasn't that he necessarily believed in mermaids — even as he urged the Academy of Sciences to launch an expedition to capture a specimen, he admitted that sightings of mermaids might be "fable and fantasy" — as that he believed such a creature was possible. Even a career skeptic like Linnaeus could hold out hope of seeing a genuine mermaid. And he wasn't the only naturalist of the age to suspect that a folkloric animal might be real; his pupil Anders Sparrman suspected that tales of unicorns spotted on the Namibian plains might, if true, explain the descriptions of such creatures in medieval bestiaries.


3. William Crookes and the Ghost of Katie King

Warning: There are going to be a lot of Victorians on this list. Magic and science, often went hand in hand in earlier eras of Western science (just look at the number of Renaissance astronomers who also worked as astrologers), but during the 19th and early 20th century, a great many scientists were particularly skeptical of the spiritualism fad. William Crookes was not one of them.

Crookes was a pioneer of vacuum tubes, inventor of the light mill (also known as the Crookes radiometer), identifier of the first known sample of helium, and an important researcher into cathode rays and radioactivity. He was also obsessed with seances and paranormal phenomena.


Like a lot of people who have been interested in spiritualism, Crookes experienced an untimely death in his family. He lost his 21-year-old brother Philip to yellow fever. Shortly after Philip's death, Crookes began attending seances. He studied mediums and declared their powers genuine. He joined the Society for Psychological Research, the Theosophical Society, and the paranormal research association known simply as the Ghost Club.

One supposed paranormal phenomenon which Crookes famously claimed was genuine was the materialization of a spirit known as Katie King. The medium Florence Cook was supposedly able to cause the spirit of a young woman named Katie King to materialize, and the supposed spirit's existence was a topic of great debate during the 1870s. Crookes claimed that he had investigated Cook and the Katie King phenomenon and published a report asserting that she was a genuine spirit. Perhaps Crookes was extraordinarily gullible; perhaps he was having an affair with the medium.

Crookes also had some influence on fellow scientist Nikola Tesla's ideas of the soul. Tesla wasn't a believer in paranormal phenomena, but he respected Crookes and thought seriously about Crookes' ideas of the spirit and life after death.


4. Alfred Russel Wallace, Friend to Darwin and Spiritualists

Although few people know about him know, Alfred Russel Wallace was, during his lifetime, famous for being one of the co-developers of the theory of natural selection, along with Charles Darwin. In fact, Darwin used Wallace's writings to inform On the Origin of Species, after which the two developed a friendship that lasted the rest of Darwin's life.

While Darwin may have respected Wallace's evolutionary theories, he was not such a fan of Wallace's views on spiritualism. Wallace didn't just attend seances and engage with supposed paranormal phenomena; he, like Crookes, was an advocate of spiritualism, a full-on convert who wrote about the subject. Wallace enjoyed celebrity status thanks to his theories on natural selection, but his views on spiritualism alienated him from the scientific community. It didn't help that Wallace would bring up spiritualism in what his peers considered improper venues. Darwin remained a loyal booster of Wallace, even if he didn't agree with Wallace's views.


Wallace was also an opponent of smallpox vaccination, but not because of his more paranormal interests. He felt that natural selection meant that everything, even smallpox, had a place in the world. Vaccination, he feared, could upset the balance achieved by natural selection.

Ross A. Slotten has written a biography of Wallace, aptly titled The Heretic in Darwin's Court.

5. Oliver Lodge, Telegraphy and Telepathy

British physicist Oliver Lodge's research aided in the development of the telegraph, but he also wondered if not just pulses and voices, but actual human thought, could be sent over long distances. Lodge is another scientist who came to spiritualism in the wake of a family tragedy, attending seances after the death of his son. His particular interest, however, was in thought transfer, and he even wrote a book on the subject, titled Spontaneous Telepathy and Clairvoyance.


As with Wallace and Crookes, Lodge's interest in unscientific phenomena and his role in legitimizing these phenomena for a credulous public earned him the ire of many of his scientific peers. However, others, like physicists Heinrich Hertz and Max Planck, were more sympathetic to Lodge's investigations into the unknown.

6. Charles Richet, Nobel Laureate with a Sixth Sense

In 1913, physiologist Charles Richet won the Nobel Prize for his work on anaphylaxis, but by then he was already fascinated by the idea of psychic phenomena. Richet suspect that human beings could project their bodily forces to trigger physical events, that humans were capable of experiencing genuine premonitions, and that humans could form ectoplasm. He wrote extensively on his theories of the sixth sense in books like Treatise on Metapsychics, Our Sixth Sense, and The Future and Premonition.


Richet was so convinced of paranormal phenomena that he, in at least one case, covered up "proof" of the paranormal that he knew was fraudulent. As a member of the Institute Metapsychique International, Richet was aware that photographs taken of the medium Eva Carrière supposedly showing ectoplasm were faked. Still, he and his fellow IMI members covered up the fraud since it provided the public with "evidence" of the psychic phenomena they believed to be genuine.

7. The Curies and the Medium

Richet isn't the only Nobel laureate who believed in the paranormal, not by a longshot. Pierre Curie, physicist and husband of Marie Curie, had a profound interest in mediumship. In particular, he was taken with Eusapia Palladino, an Italian mystic who claimed she could levitate tables and communicate with spirits. The Curies attended Palladino's seances, and were impressed to find no evidence of trickery. Pierre, in particular, seemed quite taken with the medium and her apparent powers. Days before his death in 1906, Pierre wrote to a friend about his latest experience at one of Palladino's seances, saying, "There is here, in my opinion, a whole domain of entirely new facts and physical states in space of which we have no conception."


If Pierre had lived just a little longer, he might have seen Palladino exposed as a fraud. The year Pierre died, two investigators discovered that she was secretly using her foot to manipulate objects. The next year, she was caught using a strand of her hair to move things that were out of her reach.

8. Camille Flammarion's Paranormal Belief of Life on Other Planets

French astronomer Camille Flammarion is a rather curious figure. On the one hand, he did wonders to increase public interest in astronomy, writing extensively on the subject in books and popular magazines. On the other, sometimes he was just flat-out unscientific. Flammarion caused a panic in 1910 when he claimed that the gases in the tail of Halley's Comet would extinguish all life on Earth (a claim which may have inspired The Poison Belt by Conan Arthur Doyle, another spiritualist).


Flammarion was another believer in spiritualism and reincarnation, but he also had a rather curious theory about life on other planets. Certainly, Flammarion was not the only astronomer to speculate that there might be living creatures in our solar system; what's odd is how he arrived at that notion. Flammarion's ideas about extraterrestrial life were influenced by the works of Jean Reynaud, who believed that after death, souls would travel to another planet, be reincarnated, live, die, and start the process again. Effectively, Flammarion combined the paranormal with the idea of extraterrestrial life. His ideas made it into some of his science fiction novels, which described life on other worlds.

9. The Wolfgang Pauli and the Pauli Effect

Do you know someone who seems to destroy electrical equipment just by being in the same room with it? Wolfgang Pauli was one of those people. According to superstition, when the theoretical physicist walked into a room, lab equipment would simply fail. His friend Otto Stern actually banned Pauli from his lab. And Pauli himself was a big believer in this particular superstition.


How did Pauli explain his effect on lab equipment? Well, Pauli believed that mind and matter were interconnected, and that human consciousness could have an effect on the outside world. So basically, Pauli believed he was psychokinetic.

10. Jack Parsons, Aleister Crowley's Rocket Scientist

Jack Parsons was a founding member of NASA's Jet Propulsion Lab and invented a solid rocket fuel. He was also an acolyte of Aleister Crowley and a high-ranking member of Crowley's Ordo Templi Orientis. Parsons claimed that he had once summoned the Devil and that he had conjured up his perfect woman — who took the form of his muse Marjorie Cameron.


Parsons also has a connection to another new religious movement: Scientology. The writer L. Ron Hubbard lived with Parsons and his girlfriend Betty for a while and participated in mystical rituals with Parsons. There is probably more than a little of Crowley and Parsons in Scientology's DNA.