While the Enlightenment was a crucial philosophical movement that set the stage for modernity, I think ideas like "The Kingdom of Ends" were signs of it's eventual failure.

Both Kant and Descartes open up a can of worms in the hunt for reason, but then try to wrap a pretty bow around it when they lose their way.

Descartes starts his meditations proposing that maybe reality is a demon just playing with our minds, but by the end, somehow digs up a benevolent God that solves this problem. I think it's just because he feared persecution by the Church though.

Kant actually wanted to believe that order could be converted from chaos through reason, but ultimately creates a magical realm of transcendence, probably out of frustration.

Sounds critical, but it's just natural. Each thinker along history picks up the ball for a little, plays with it, ending in some contribution to thought, then drops it for someone else to take a shot. We're left with a pretty cool collection of perspectives.