On the Oracular Order, By Douglas Harwickle, Historian is a book found in Dishonored 2.
Much has been said about the blind Sisters of the Oracular Order. In truth, their eyes function just as well as yours or mine. However, they do endeavor to become blind to distractions and frivolities. They will, if necessity bids them, walk among us, wearing richly hued blindfolds or otherwise covering their eyes. In this way they remain "at all times ready to see things clearly."
Decisions are made during Cloistered Gatherings. Though no others are permitted to observe, the process was described to me, so I render it here with permission.
"A room is prepared with heavy incense and blessings from the Strictures. In a circle sit thirty or more Sisters of our Order, until the room is brimming. We will hear no topic, lest we have each had adequate time to research. Several outcomes will be discussed, and some Sisters are specifically tasked with advancing less popular or unlikely scenarios. It is not permitted to remain silent. Every voice must be heard. It may take some time to arrive at a decision, and by then all are quite versed in the myriad consequences, and may have lengthy advice for all contingencies. When an opinion is written, it may be as short as a sentence, or fill twenty pages. Yet still, one last Sister must approve it, the High Oracle herself."'
This book can be found in several locations: