This illusory power came from the rise of "public opinion", born when absolutist centralization removed the nobility and the bourgeoisie from the political sphere. Philosophers and Scientists committed the fallacy of argumentum ad ignorantiam.
When we reflect on first-order passions such as gratitude, kindness and pity, we find ourselves approving or liking them and disapproving or disliking their opposites.
More on the effects of the Enlightenment.
In the Treatise on SensationsCondillac attempts to explain how all human knowledge arises out of sense experience. But Cleanthes is not moved. Madison argues that popular government pure democracy is subject to the evil of factions; in a pure democracy, a majority bound together by a private interest, relative to the whole, has the capacity to impose its particular will on the whole.
However, skepticism is not merely a methodological tool in the hands of Enlightenment thinkers. The powers and uses of reason had first been explored by the philosophers of ancient Greece. Thus, the good of things, including human beings, for Shaftesbury as for Clarke, is an objective quality that is knowable through reason.
The relation of Descartes to the philosophy of Enlightenment In France and in England, all the philosophical thoughts from the middle of 17th century through the 18th century were under Descartes's influences. This ordinary sense of moral requirements is not easily accommodated within the context of Enlightenment empiricism and naturalism.
Fontenelle's philosophy did not accept the Cartesian spiritualism and overemphasized the positive elements of the Cartesian philosophy. Developing natural science renders acceptance of a literal version of the Bible increasingly untenable.