"Creativity depends on the union of things that are also maintained separately – the precise function of the corpus callosum, both to separate and connect; and interestingly division of the corpus callosum does impair creativity." (The Master and His Emissary, Iain McGilchrist, 2009; somewhere between page 41 – 50).
A properly functioning priesthood is the nation's corpus callosum between the divine and the mundane.
According to that model, if the priesthood ceases to function properly, the nation should lose a substantial measure of its creative capacity. It will find itself stuck in trying the things that worked in the past, unable to dislodge itself from the rut of the well worn.