As I have noted before, we don't actually know for (one hundred percent) who created the original outline of the rituals contained in the Cipher Manuscript. For simplicity's sake, let refer to him or her as person C. Now, it is more likely that it was a man who created the rituals, so I am going to refer to them as a Frater for the rest of this post...and for the rest of this series for that matter. Hence, Frater C is whoever created the first outline of the Golden Dawn rituals.
(I would also like to use the honorary "S.H." for them, but the use of that implies that they were much higher in the system than some are willing to give them credit for...therefore I will only say it in my head as I write this post.)
Today, the general rule is "Do not mix systems" unless you are an expert in them...or a chaos magician (I can't imagine a chaos magician reading my blog...but it could be happening...*waves hi at the chaos magician in the crowd*). This rule has not always been the standard. Heck, even in this generation, it is not always the standard...my first Wiccan mentor used the rule "Use whatever works best for the job at hand" and occasionally that meant using the symbols of one system with the techniques of another system.
When we look at the Cipher Manuscript, we see a remarkable mixture of symbols and techniques taken from various systems and cultures. A question naturally arises from this fact.
"Why did Frater C mix systems in the Cipher Manuscript?"
My answer is that Frater C was a product of his time period, just like the Cipher Manuscript is. While others argue an earlier origin for the Golden Dawn system, it is my belief that it is a product of the Victorian Age. Today, we think of the Victorian Age as a conservative time period---and forget that England went from a farming based economy to an industrial based economy. Labor rights, women rights, and the roots of the New Age movement were all developments of this time period in England. We are looking at the dawn of industrial world...and it all happened during the lifetime (a long lifetime) of a single Queen.
Now, one of the things going on in England was what some refer to as "The Golden Age of Fringe Masonry." Or as I like to refer to it, "The Golden Age of Loony Secret Societies." The hundred years from 1850 to 1950 is the most fertile time for the lodge system. The birth of the lodge system is often said to be 1717, when three Freemason lodges in London formed a Grand Lodge, but the lodge system actually predates that year---1717 is the birth of the Grand Lodge system, lodges existed before that time.
The lodge system is actually a product of England. Or at least, lodges using "lodgekit" are. Secret societies existed before the birth of the Grand Lodge system, but the Grand Lodge system changed how they worked. And inside the realm of spiritual development, the lodge system has no counterpart anywhere else...wherever you see lodges, you feel the touch of the English.
Now previous to the start of the Golden Age of Loonies, the rituals practiced by lodges were simple affairs. But as the number of Orders exploded during the Loony period, the rituals got more and more complicated. To explain why, we must remember that lodge membership was a big business and a source of entertainment for its members. The capstone for entertainment value was when one Order created a set of rituals around the novel, Ben-Hur.
Any culture that was not bolted down became fair game. This included the spiritual systems. Now, the lodges tended to not mix systems. But this changed as the age went on.
Part of the reason is the explosion of the spiritual and Theosophical movements. (Think New Age if you want to consider a modern counterpart.) The Theosophical movement was very much into mixing systems together. And the Theosophical movement was busy taking away potential members.
When you actually start looking for mixing of systems, history is full of examples. The Roman Empire, Graeco-Egypt, the Medieval Age, the Fama of the RC, can all be mined for examples. There is nothing quite like the reading of medieval literature and encountered Isis as an example of a saintly woman. And Frater C would have known this.
One can see that it is not always "Do not mix systems." Often, it is "Take whatever will work the best and use it." And Frater C willingly grabbed anything that was not bolted down. It is reasonable to assume that Fracter C was aware of the Theosophical movement. And while he was not into the entertainment side of the lodge system, he did know that the English occultists of the day were willing to borrow from any system they could get their hands on. Call it a form of Magical Imperialism. Of course, knowing why he mixed system just leads to other questions that must wait for another day...or week...or however long it takes to rotate around to them.