This video discusses a rhetorical device, or a "rhetorical idiom," that traps the speaker and produces an effect contrary to their intention. The speaker defines this as the "bias of thinking others are intellectually inferior," differentiating it from the Dunning-Kruger effect. It's presented as a form of "epistemic arrogance" where one overestimates their own knowledge and underestimates others, leading to a reduction in the scope of unknown possibilities. The video explores three main assumptions that fuel this bias: the assumption of ignorance, the assumption of idiocy, and the assumption of malice.