Complex sentence: The "Deity mode of speech" refers to a perceived misuse of the verb'to be', which "allows even the most ignorant to transform their opinions magically into god-like pronouncements on the nature of things".
Split into simpler sentences: The "Deity mode of speech" refers to the use of the verb'to be' to assert universal truths which are actually subjective observations. It "allows even the most ignorant to transform their opinions magically into god-like pronouncements on the nature of things".