Consensus versus dissent arises as an issue in science because of science's aspiration to universal assent, a goal that is a secularized version of the universalist aspirations (see universalism versus relativism) of the great proselytizing religions, Christianity and Islam, according to which the truth is not fully realized until it is accepted by everyone. This made science central to the emancipatory project that democratic activists, especially socialists, derived from the eighteenthcentury Enlightenment. (See science as a social movement, social science.)

Here it is worth observing that, with the possible exception of the Sophists, the Greeks had not generally presumed that an objective and rational account of reality would be accessible to all human beings, let alone derive its epistemic merit from such accessibility. (See rhetoric.) Indeed, Plato was quite explicit that hard class divisions are ultimately justified in terms of clear differences in epistemic access. When Aristotle declared that the pure pursuit of knowledge required leisure, he was not recommending (as Karl Marx's son-in-law Paul Lafargue did) mass laziness; he was laying down a class marker that only the already leisured were in a position to know. analytic social epistemology continues this tradition by requiring consensus only at the second-order level of epistemic analysis, that is, there should be universal agreement over who holds the relevant expertise in a given situation where a decision needs to be taken.