Absolutism concentrated political power in a single monarch whose authority was claimed to derive directly from God rather than from any earthly institution, court, parliament or nobility, that could legitimately constrain it. Enlightenment thinkers writing across the following century developed a systematic set of philosophical arguments, grounded in reason, natural rights and the idea that government's legitimacy has to rest on the consent of the governed, that directly challenged any monarch's claim to that kind of unchecked, unaccountable authority.
Absolutist monarchs claimed authority that answered to no earthly check
Louis XIV of France stands as absolutism's clearest example, centralising administration, maintaining a large standing army answerable directly to the crown, and deliberately weakening the independent political power the nobility had once held, partly by drawing them into ceremonial life at a single centralised court at Versailles rather than let them govern their own regional power bases. The underlying justification was divine right: the monarch's authority came from God, not from any human institution, which meant no earthly body, parliament, court or noble council, had any legitimate standing to limit it.
Enlightenment philosophy built the intellectual toolkit that undermined that claim
John Locke argued individuals held natural rights that existed independently of any government, and that legitimate government rested on the consent of the governed rather than divine appointment. Montesquieu argued that concentrating all power in one person or body was itself dangerous, proposing separated powers as a structural check. Rousseau developed social contract theory further, framing legitimate political authority as something a people collectively agreed to rather than something a monarch simply possessed by birthright. Together, these arguments supplied the intellectual vocabulary later revolutionaries in America and France drew on directly.
What we're still unsure about
That absolutist monarchs claimed divine, unchecked authority, and that Enlightenment philosophers developed systematic arguments against that claim, are well established, extensively documented intellectual and political history. What's more genuinely a matter of ongoing historical debate is exactly how directly Enlightenment ideas caused the revolutions that followed, as opposed to supplying a retrospective, ready-made justification for political and economic pressures that were already building for other reasons, and historians continue to actively debate that relative causal weight for specific revolutions rather than treating the philosophy-to-revolution pipeline as fully settled.
This sits inside Absolutism & the Enlightenment, one of eight topics in Early Modern History, one of seven domains in History, one of seventeen subjects the app can quiz you on.