This, in a nutshell, is how I reconcile magickal practice and the understanding of reality we get from the natural sciences.
I take Uncle Al's maxim “The Method of Science, the Aim of Religion” to mean that magick is to one's personal, subjective experience of one's life as science is to the physical universe. Your life is the material you're working with in magick.
Obviously your subjective experience is profoundly conditioned by your encounter with the material cosmos. What you see is shaped by what's in your head, yes. But what you're looking at, outside your head, also has a big effect. (At least, it does if you're sane.)
Science organizes the application of reason to the physical universe through the use of meticulous experimentation and observation within controlled conditions, confirming its models of the world through reproducible results. These rigorous standards produce High Quality Truth. Let me say that again. Science produces High Quality Truth. If you are wise, you will not fuck with it.
Magick organizes the application of reason to your life through the use of meticulous experimentation and observation ... but in your life you cannot have controlled conditions, and you cannot get neatly reproducible results. In studying your life, it is impossible to use the full rigorous standards of science. But you can still apply reason and experiment to get very useful results.
Science produces models of how the physical universe works. Models are regarded as strong to the degree that they predict what the universe does, using the simplest explanation of the widest range of phenomena. Again, this marvelously rigorous standard gives us extremely reliable models. These models tell us that at the scale we live in the cosmos has crisp, mechanical rules for causality in which the operations of the mind do not directly affect what the cosmos does.
Yeah, yeah, quantum mechanics, I know. QM does not apply at human scales. Do not kid yourself with some What The Bleep bullshit about how QM proves that the universe is just craaaazy. It does not. That is fucking with the High Quality Truth of science, and I warned you about that. The world of people and teacups and cheeseburgers that we live in is Newton's clockwork automaton. But don't worry, it has plenty of room for magick.
Magick produces models of how your life works. Consider two types of models that can describe the effects that you get: Consciousness and Spookiness. In the Consciousness model, you understand a magickal operation as having altered the processes of your mind, resulting in changes in behavior and perception that produce the effects that you get. In the Spookiness model, you understand a magickal operation as having connected to spooky patterns in the cosmos (gods! angels! demons! egregores!) which use spooky means to reshape the cosmos, bringing the effect to you.
Both models provide explanations of the results you get from magickal practice. Early in your magickal practice the Consciousness model seems tidy and straightforward — “after the ritual for A New Job, I started talking to people about A New Job more, started preparing for it, started looking for it, so it's no surprise that I was able to bring myself A New Job when I bumped into it in the form of Jane at that cocktail party” — while the Spooky model seems elaborate and tortured and, frankly, a little goofy. This is comfortingly consistent with Newton's clockwork universe that we know about from science; you can see all the material, causal connections at work. But as your magical practice progresses, the Consciousness explanations you can come up with for the magickal effects you get become increasingly elaborate and tortured ... while the Spooky explanations become increasingly tidy and straightforward.
Models should be regarded as strong to the degree that they predict what your life does, using the simplest explanation of the widest range of phenomena.
Both explanations will always continue to apply. You will never get magickal results that outright conflict with a Consciousness model consistent with the scientific understanding of the material world. But your life is inherently a great big irreproducible result, with plenty of room for the improbable. Looking at your life, performing magickal experiments, seeking the simplest explanation, things can get very, very Spooky.