97. The contradictions that often appear in what spirits say should come as a surprise only to observers who merely possess an incomplete understanding of the Spiritist science. Contradictions result from the nature of the spirits themselves, who, as already stated, can only understand matters according to how evolved they are; many of them know even less than certain incarnates. Regarding a multitude of facts, they can provide only their personal opinion, which may be correct to some degree while still reflecting the earthly prejudices they have not yet abandoned. Others fabricate their own theories about what they do not yet understand, particularly regarding scientific matters and the origin of things. Consequently, it should come as no surprise that they are not always in agreement with one another.