The basis of the Lorite order is Saunt Lora's Proposition which states that all possible ideas have already been found, in other words, there is nothing new to discover. The Proposition itself is considered to be the Last Idea, although after the death of Saunt Lora, one of her fids showed that her proposition had itself been expressed 4000 years earlier.
By the time the novel opens a strict reading of Saunt Lora's Proposition is maintained only by orthodox paleo-Lorites. (It is not clear if this is the name for an order, or a description of some Lorites). Modern Lorites act as historians, and will point out new ideas which were expressed in the past.