Occult Day

What the day is

Occult Day is observed on November 18. The word comes from the Latin occultus, meaning hidden or concealed, and it is used in astronomy in exactly that neutral sense: an occultation is when one body passes in front of another.

Applied to belief and practice, occult covers traditions concerned with hidden knowledge: alchemy, astrology, ceremonial magic, divination and the esoteric societies built around them.

Origin and background

The origin of the observance is not documented.

The historical importance of these traditions is easy to underestimate because their claims did not survive. Alchemy is the clearest case. Alchemists never transmuted lead into gold, but in pursuing it they developed distillation, crystallization, sublimation and a great deal of laboratory apparatus and technique that chemistry inherited directly. Isaac Newton wrote more on alchemy and biblical chronology than on physics, which his later admirers found embarrassing enough to suppress.

Astrology similarly drove centuries of careful astronomical observation, because casting accurate charts required accurate planetary positions. The data outlived the interpretation.

The nineteenth-century occult revival in Europe and America intersected with art and literature to a remarkable degree, and its vocabulary reached psychology through figures interested in symbol and the unconscious. Modern fantasy and horror draw on the same well almost entirely.

Two things are worth holding together: these practices produced real intellectual byproducts and built real communities, and their central claims have not been supported by evidence. Both can be true.

How to take part

• Read about the history rather than the practice. The alchemists' laboratory work is genuinely interesting.
• Look up Newton's alchemical papers and what his biographers did with them.
• Watch an actual astronomical occultation if one is visible; the word's original meaning is worth seeing.
• Read a gothic novel or a ghost story, which is where most of this material now lives.
• Treat anyone selling certainty about the future with the skepticism you would apply to any other transaction.