Two Enlightenments

Jonathan Israel ( A Revolution of the Mind: Radical Enlightenment and the Intellectual Origins of Modern Democracy ) distinguishes between a “radical” and “moderate” Enlightenment, locating the main difference in metaphysics rather than national setting or politics:

“Beyond a certain level there were and could be only two Enlightenments – moderate (two substance) Enlightenment, on the one hand, postulating a balance between reason and tradition, and broadly supporting the status quo, and, on the other, Radical (one-substance) Enlightenment conflating body and mind into one, reducing God and nature to the same thing, excluding all miracles and spirits separate from bodies, and invoking reason as the sole guide in human life, jettisoning tradition.  There was a closely allied variant of the latter, also part of the Radical Enlightenment, in the shape of philosophical Unitarianism, a variant almost as relentless in proclaiming reason as the sole guide, rejecting tradition as the source of authority and denouncing the existing order more or less in toto.  The essence of the Radical Enlightenment both in its atheist and Christian Unitarian modes was that ‘reason, and law founded on reason,’ as the point was expressed by Nicolas-Antoine Boulanger (1722-1759) in a classical text of radical philosophical literature, ‘should be the only sovereigns over mortals.’”

This was not a simply difference between theists and atheists.  It was more a difference between Spinozists and everyone else:

“the sort of ideas diffused by Diderot, d’Holbach, and their disciples in the 1770s and 1780s had an essential ‘Spinozist’ philosophical underpinning in that they envisaged philosophical reason as the only guide in human life, sought to base theories about society on the principle of equality, and separated philosophy, science, and morality entirely from theology, grounding morality . . . on secular criteria alone and especially the principle of equality.  Radical Enlightenment was further quintessentially defined by its insistence on full freedom of thought, expression, and the press, and by identifying democracy as the best form of government, features against specifically Spinozistic and in no way Hobbesian or, in the latter case, Humean.  Neither did radical thought have anything concretely to do with Locke and still less . . . with the English Commonwealth tradition or Freemasonry.  Without classifying radical thought as a Spinozistic tendency combining one-substance doctrine or philosophical monism with democracy and a purely secular moral philosophy based on equality, the basic mechanics of eighteenth-century controversy, though, and polemics cannot be grasped.”