What are the transmutation circles in Fullmetal Alchemist based on, if anything?


The transmutation circles in _Fullmetal Alchemist_ always looked familiar to
me, but I could never place my finger on why. What, if anything, are they
based on?

[![Human Transmutation
Circle](https://i.stack.imgur.com/dmAaDm.jpg)](https://i.stack.imgur.com/dmAaD.jpg)




This site has a note about ["Squaring the
circle"](http://alchemicalpsychology.com/new/5.htm), describing a utilization
of circles:

![enter image description here](https://i.stack.imgur.com/nhsxr.jpg)

Attributed to [Michael Maier](http://en.wikipedia.org/wiki/Michael_Maier), a
German alchemist from the 17th century. That gives you the generalized
"simple" transmutation circle:

![enter image description here](https://i.stack.imgur.com/HAFzX.jpg)

The symbols used in some of the more complex circles are old alchemic symbols
or variations of them. I don't know of a complete list of them but some of
them can be seen in [Annibal Barlet's
works](http://www.alchemywebsite.com/symbols_barlet.html) or other symbols
from the [17th century](http://www.alchemywebsite.com/val_symb.html). The
inscriptions themselves seem to mostly come from [George Ripley's 12
Gates](http://www.levity.com/alchemy/ripgates.html).

