So, for the purposes of this discussion I want describe my views of the magic.
Shamans use things, activities, ideas, in order to change their mind-state. These alterations of mind can be distinctly known as a change in the world of oneself. Because what we know is only us, so changing us changes our view. I am not proposing upward causation, from the mind to the world, but rather an appeal to naive-idealism, the mind in the world. We can't live forever, but we can make now pretty good for us.
This act of knowing ourselves, where we end and begin, is the first steps toward the shaman.
The shaman may employ other tactics to know themselves. Rather than changing themselves they alter the world. Pick pieces and blocks and paste them all together. This is alchemy.
Alchemy is known as both a practical predecessor to modern chemistry and a metaphor for spiritual work. We can see both of these tactics(practice and metaphor) in the shamans works. Obviously chemistry is a response to the desire for change, and spiritual work is that desires playing out. He knows the world, and he knows himself. He uses the world to change himself, and integral to using the world to change himself comes another change to his view of the world.
This loop of logic is a cornerstone of our practices.