In Software Project Management, we develop software applications or database schemas based on requirements. Requirements are identified by business needs. Say Management needs to be able to see how well one product has sold for the past twenty-five years to decide whether to continue pushing it during the recession. They describe the report they want to see to the person that manages the data. When you begin to plan the development project, you start with your business case, establishing why it's necessary to have whatever you're developing. You detail the scope (it'll go back 25 years, not 50, or it will include only these products, not those), and you use your scope and your business case to build out your "requirements." Requirements become Design Specifications, and the Design Specifications become the software code that extracts specific data from the database and sends it to the report tool that shows the Management guys what they need to see. The quality assurance team develops Test Plans from the Requirements, to make sure the finished product does what it is supposed to and fulfills the business need.
So Requirements are important things to identify. You can't develop something efficiently without knowing what it's supposed to do.
But there's another piece that must be included: ASSUMPTIONS. Assumptions list the things that the developers and project managers don't know, but have to be true for the Requirements to be valid, and the code to do what it's supposed to. Like, in the example above, we would assume the Management knows how to read the report, or that the report tool is already there and that we know how to load the data into the report tool already and we won't get to the load stage and run into a brick wall because by the way, management wants you to use Crystal Reports to generate an Adobe PDF to present the data, not an Excel spreadsheet. Didn't we mention that? Documenting the assumptions provides a means to say, look, this is what we're assuming is true before we begin, so if it ain't right, you'd better tell us now in the early stages of the project before we hit that wall.
The Grimoires don't have an assumption list. They have the requirements listed fairly well (on the ninth hour of the night, you can conjure spirit X using sigil Y and God Name Z). They have the Specs detailed (9 foot circle, gold talismans for solar work, silver for moon, etc). They have the scope (this spirit gets you that result, not the other).
But they don't have the assumptions listed. They don't tell you that, oh, for instance, that you'd better have received a baptism of the Spirit before you try to step foot in a circle and try to tell a Goet what to do.
I posted a picture a while back of a dude parachuting into a pool in a jungle surrounded by crocodiles and labeled it a magician without K&CHGA working Goetia. It was somewhat tongue in cheek. However, there is a spiritual transformation that has to take place in a person before they are ready to be playing with the spirits of the Goetia and getting the kinds of results I and many others receive. You need something like K&CHGA. You need the empowerment of the ten angels of the spheres listed in the Circle of the Goetia. You need all that, but you need a rebirth.
You were born into a world of blood and sweat and tears. You excrete and exfoliate. You drip and drop bits of your flesh wherever you go. That body you walk around in is literally falling apart. And you think that's you. When my kids are bickering, one will touch the other to annoy them, and they'll say, "Quit touching me!" They don't know that their bodies aren't them. They don't get that they're eternal spirits in a temnporary flesh suit. Bill Cosby says they're brain damaged, but I think it's something more than that.
We identify from birth with our body. Keeps us alive. That's a good thing. But it doesn't get us ready to conjure spirits. What that takes is a vision of the Universe that reveals Who we are and What we are, and what our place in everything is.
Plotinus calls it reclaiming our Race and Value. He recommends contemplation of our Source to remember that we are eternal. It takes an understanding of what you need to contemplate of course, your source being prety far removed from your flesh. I suggest reading Iamblichus to understand how bodies and spirits and gods and daimons all interact together. I think meditating on what a Hero is in Iamblichus is awesome for people to get towards the spiritual rebirth.
But there's more to it. You need to get the shit knocked out of you. You need to see it, see eternity laid out in front and behind you, see the hierarchies of spirits in all their glory, each working on their assigned tasks. The HGA can do that for you. Baptism in the Holy Spirit can do that for you. The empowerments of the tantrickas seem to have done it well for Jason.
If you haven't, then leave the Goetia alone. You're going to run into a wall. You won't get the results you're looking for, you'll think magic is bunk, or worse, you'll end up stirring up crap and starting a new chain of stupid horror stories about the Goets that aren't true for anyone with the balls to look for the unlisted assumptions.
Stick to the Angels, they'll get you where you need to be, and they can do most of what the Goetia spirits can do, eventually. Remember, the Emerald Tablet has you rise first, and then return to the Earth in Power. Too many people want to just have power on Earth without rising through the spheres. It doesn't work that way.