I received my copy of Gateways through Stone and Circle by Frater Ashen Chassen not to long ago. (I still owe you a selfie, frater!). I've read the introduction, and the account of the summoning of Cassiel. It read much like my own summoning of Agiel (an angel of Saturn, instead of the Archangel). There were quite a few similarities in the accounts.
I also read the introduction, which mentions that this is an obscure hobby. It truly is, and the fact that I know about 50 people who practice it is a testament to the power of the internet to join together people who have obscure interests.
Rufus Opus just recently mentioned that we don't know how magic works, and that terrible things can happen as a result of doing the operation he proposes (7 spheres in 7 days). I recently did an planetary ascent cycle, where I contacted each planetary sphere on it's day, in ascending order (Monday, Wednesday, Friday, Sunday, Tuesday, Thursday, Saturday in two week cycle). It gives a day in between to equilibriate the energies of the spheres.
I object to the idea that 'we don't know how magic works'. We may not know the exact mechanism, but we do know that a) certain actions provide certain results, and b) those results are not always exactly as anticipated from the actions. Magic is a work that bridges the internal-unseen with the external-unseen, the unconscious with the universal unconscious, the soul with the spiritual realm. It opens a floodgate for energies to flow from one to the other, and cause effects in both places. Sometimes, the effects are unintended. We see this all the time, when we introduce energy into a material framework. Too little, and nothing happens. Too much, and things combust. Finding that right balance is the major effort of the engineering discipline.
When we do a summoning or a spell or a working to affect an external happening (find a job, find love, etc) we're allowing those energies to enter our internal worlds, and our internal desires to have an external expression. In the beginning, when first starting out, we have very little control over what gets in, and what gets out.
It's dangerous letting anything escape our internal worlds. Ideas, hopes, dreams, intentions: they're all subject to the hostilities of the outer world as soon as they leave our brains and lips. Criticism, trolling, and simple dismissal will meet anything we through out there. The universe is hostile, so impersonal.
But our ideas, hopes, dreams, and intentions have to brave the hostile universe in order to manifest. Unless we are there to support them, they will be devoured. So we wrap them in ritual, and we thrust them into the universe, clothed in angels wings, protected by omens and auguries, timed perfectly to have the light of this or that deity shine upon them. We color our auras and feed energy into our projects, we ask for divine protection.
And in return, we take in those qualities of that which we beseech. The Jupiterian supplicant becomes generous, expansive, jolly. The Martian supplicant becomes aggressive, passionate, willing to fight for ideals or simply for the joy of destruction. The Solar supplicant fills with beneficence and radiates love, growth, and light.
Magic is a two way street. We transform the world by transforming ourselves. Transformation is both destructive and creative. It is the introduction of energy to overcome inertia, and in the overcoming we both destroy and create, we transform, we change, we consume and produce. And it's not easy, nor simple, nor always what we expect.
Without the effort, the taking in and pushing forth, nothing changes.