There are many secret societies around - most hearkening back to the early times of science and philosophy. Some of these societies are still around today like the FreeMasons but many are lost in time. And some are buried deep within other secret societies creating even more mystery and intrigue. Take for example the Copiale Cipher which is one of those secret societies (called the Ocultists) within a secret society. Interestingly the Oculists’ insignia show cats watching over mice. It could be an Oculist joke — or a sign that they were spies.
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Here is a link to the full article on the Copiale Cipher which tells the story of how the full translation unfolded. And for those who prefer video, check out this overview: