We often fail to take the scientists at their word.
They meant for their "En-LIGHT-enment" project to be taken literally.
They had a determination to turn the full light of scientific curiosity upon that childhood darkness that lies at the top of all of Humanity's stairs, because they were certain to the point of certitude -They Had Faith - that it would turn out to be more simple, more regular and more benign than our dirty,cluttered day-to-day visible world.
Our fears of these dark unknown areas they dismissed as superstitions promoted by priests.
So between 1895-1945, we got ever more powerful searchlights that probed the skies above us or the seabed deep beneath submersibles.
In wartime, they served to coned Allied bombers high in the air or to Leigh-ted up U-boats lying low on the surface of the sea.
Bigger and bigger telescope lens or mirrors gathered up more light and concentrated it, letting us see further and further in Space and further and further back in Time.
With newer microscopes, we added ever sharper lights to ever more powerful lens, to clearly see Brownian motions and thus see the motion of molecules.
But ultimately there is a limit to the sharpness of visible light, so we expanded into X-Rays (circa 1895) to peer into bodies, metals and crystals and molecules and then Radar (circa 1945) to see into clouds and darkness and finally to bounce off of the Moon itself.
We developed flash photography, in ever shorter, sharper bursts so we could clearly photograph a speeding bullet stopped in mid-flight.
The electron microscope uses a sharper (a shorter wavelength) form of illumination to reveal a lot more of the hidden details of bacteria
and to show us viruses and even atoms for the first time.
If an atom buster ray can be thought of as a form of light, it too revealed much that was new - in particular the world of sub-atomic particles, indirectly visible as con tails in cloud chambers or revealed on exposed film.
New radio telescopes (circa 1931) listened to waves of information coming into us from the darkness of the universe - as did cosmic ray detectors.
All of this before 1945, Auschwitz, Hiroshima, et al.
The Enlightenment didn't die or fail - it succeeded only too well in revealing what lies in those areas of Reality beyond our normal ken - but it was totally wrong in assuming that they would be simple,regular and benign.
Perhaps Adorno and Horkheimer wrote their famous little mimeographed book a little too early.
Because they failed to understand that the deliberate 'return to darkness' of post 1945 Film NOIR might have been a reaction against all the bright enlightenment that the previous half century had produced...