Doesn't that man know anything? Of course it's not hard to summon an angel- nay, an archangel. You just have to speak their name in the time of the day of the week that they rule over.
This much I have learned:
There are seven Governments of the Spirits of Olympus, appointed by God to govern the entire universe. Their stars, visible to the naked eye, are: ARATRON, BETHOR, PHALEG, OCH, HAGITH, OPHIEL, PHUL, in the Olympick language. Each one has under him a powerful angelic militia
stationed in the firmament.
The Princes of the seven Governments are summoned simply, in the time, day, and hour, in which they rule, in its visible, or invisible part, in the luminous, or dark part of the week. They are summoned by their Names and their Offices given to them by God; and by drawing their Seal which they have themselves given, or confirmed, to the Magician.
Thus, ARATRON appears if he is summoned in the first, visible or invisible, hour of Saturday, and not, for example, in the sixth hour of Tuesday; just as PHALEG appears if summoned in the first, visible or invisible, hour of Tuesday and not, for example, in the third dark hour of Saturday; OPHIEL appears on the first hours of Wednesday; Bethor on the first hours of Thursday; and so on, and so forth. And each of them gives true answers concering his Province, and his Provicinals. So do the other Olympians then appear in their own days, and hours, of the week.
And this information is easy for anyone to find on the internet, with but a simple search. For the wisdom of the ancients and their knowledge of time and the heavens is still available to us. So I don't understand how someone who professes to know so much about the summoning of demons, and now, angels, as Eliezer Yudkowsky, would ignore it.