according to Khan Academy : The Enlightenment was an intellectual movement in the eighteenth century that emphasized reason and science.

according to René Guénon : The tendencies that found expression among the Greeks had to be pushed to the extreme, the undue importance given to rational thought had to grow even greater, before men could arrive at 'rationalism', a specifically modern attitude that consists in not merely ignoring, but expressly denying, everything of a supra-rational order.

Henceforth, there was only 'profane' philosophy and 'profane' science, in other words, the negation of true intellectuality, the limitation of knowledge to its lowest order, namely, the empirical and analytical study of facts divorced from principles, a dispersion in an indefinite multitude of insignificant details, and the accumulation of unfounded and mutually destructive hypotheses and of fragmentary views leading to nothing other than those practical applications that constitute the sole real superiority of modern civilization - a scarcely enviable superiority, moreover, which, by stifling every other preoccupation, has given the present civilization the purely material character that makes of it a veritable monstrosity.