The Enlightenment often brusquely denied the possibility or importance of the transpersonal, yet it turned out itself to be the beginning of SBNR. It did scour away a lot of religion, especially the remains of Catholic hegemony in France. And Voltaire was a deist, not an atheist.
The Enlightenment brought in values of freedom to which SBNR holds and is beholden. It said: believe freely, although not without good reason, and don’t debar others from expressing different views. SBNR still says this. SBNR is founded on reasonable social principles.
It is partly Enlightenment empiricism itself that has lifted the ban on the transpersonal. If we experience something, it is reasonable to believe we experience it, especially when we can measure its correlates. That is the position of every NDEr, every Kundalini meditator, every Old Hag experiencer…
Of course we had no definite idea that these things existed when the Enlightenment set it all in train. We know now only because a lot of good people went to the trouble of finding out, and also because we have the freedom of speech to talk about it, itself a fundamental of the Enlightenment aims.
SBNR as a milieu isn’t possible without a certain degree of public freedom.