Liberalism and enlightenment are sometimes taken as synonymous. It is true that they are both indispensable pillars of human progress and rose intertwined to preeminence in the middle of the 18th century.
Enlightenment traces its origins to Descartes' Discourse on the Method, published in 1637, while John Locke’s Two Treatises (1690) established the liberal idea that government acquires consent to rule from the governed, not from supernatural authorities. However, they can develop separately and do not need to tag along, in the way the scientific method and the enlightened virtues do.
Besides, there are two distinct schools of enlightenment, the French Enlightenment focused on the power of reason and the members of the British Enlightenment emphasizing its limits. For an excellent summary contrasting the role of these views on reform and gradualism read this post by David Brooks on two theories of change.