Isaiah Berlin summarized the Enlightenment ideals in these three premises, which Enlightenment thinkers held with religious-like fervor (to David Hume's amusement and, later, to Dostoyevsky's disgust):
1. Every genuine question can be answered. If it can’t be answered, it’s not a genuine question.
2. The answers to the questions can be discovered, learned, and taught.
3. All the answers are compatible with one another.
Those ideals are captured perfectly by science. Science is the discipline of power: it answers questions and puts them into neat boxes. Physics is especially good at this.
One of the (many) problems with this:
"The most important questions are, precisely, the unanswerable ones." Iain McGilchrist, The Matter with Things, p. 46
The Tie to Gnosticism
"True" gnosticism, which I refer to as "political gnosticism," is apocalyptic or revolutionary. It shares common ground with the Enlightenment "Three C's": certainty, cockiness, and control, but it takes the C's to a feverish level and demands change to match their worldview.
Cultural gnosticism shares the Three C's, but it doesn't have the revolutionary fervor or sharp political angle. It's a worldview, yes, but not frothing.
The Three C's are dominant traits of the left hemisphere's way of attending to the world, hence the reason "gnosticism" is always left hemispheric. Any person governed by his left hemisphere is at least "gnosticish," and at some point, he tilts into full-blown gnosticism ("political gnosticism").
I perceive it as a spectrum disorder.